diff --git a/appstoreserverlibrary/api_client.py b/appstoreserverlibrary/api_client.py
index 890cdfef..1289186f 100644
--- a/appstoreserverlibrary/api_client.py
+++ b/appstoreserverlibrary/api_client.py
@@ -319,6 +319,13 @@ class APIError(IntEnum):
     https://developer.apple.com/documentation/appstoreserverapi/invalidtransactiontypenotsupportederror
     """
 
+    APP_TRANSACTION_ID_NOT_SUPPORTED_ERROR = 4000048
+    """
+    An error that indicates the endpoint doesn't support an app transaction ID.
+    
+    https://developer.apple.com/documentation/appstoreserverapi/apptransactionidnotsupportederror
+    """
+
     SUBSCRIPTION_EXTENSION_INELIGIBLE = 4030004
     """
     An error that indicates the subscription doesn't qualify for a renewal-date extension due to its subscription state.
diff --git a/appstoreserverlibrary/jws_signature_creator.py b/appstoreserverlibrary/jws_signature_creator.py
new file mode 100644
index 00000000..491e9f8b
--- /dev/null
+++ b/appstoreserverlibrary/jws_signature_creator.py
@@ -0,0 +1,140 @@
+# Copyright (c) 2025 Apple Inc. Licensed under MIT License.
+
+import datetime
+from typing import Any, Dict, Optional
+import base64
+import json
+import jwt
+import uuid
+
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import serialization
+
+from appstoreserverlibrary.models.LibraryUtility import _get_cattrs_converter
+
+class AdvancedCommerceAPIInAppRequest:
+    def __init__(self):
+        pass
+
+class JWSSignatureCreator:
+    def __init__(self, audience: str, signing_key: bytes, key_id: str, issuer_id: str, bundle_id: str):
+        self._audience = audience
+        self._signing_key = serialization.load_pem_private_key(signing_key, password=None, backend=default_backend())
+        self._key_id = key_id
+        self._issuer_id = issuer_id
+        self._bundle_id = bundle_id
+
+    def _create_signature(self, feature_specific_claims: Dict[str, Any]) -> str:
+        claims = feature_specific_claims
+        current_time = datetime.datetime.now(datetime.timezone.utc)
+
+        claims["bid"] = self._bundle_id
+        claims["iss"] = self._issuer_id
+        claims["aud"] = self._audience
+        claims["iat"] = current_time
+        claims["nonce"] = str(uuid.uuid4())
+
+        return jwt.encode(claims,
+            self._signing_key,
+            algorithm="ES256",
+            headers={"kid": self._key_id},
+        )
+    
+class PromotionalOfferV2SignatureCreator(JWSSignatureCreator):
+    def __init__(self, signing_key: bytes, key_id: str, issuer_id: str, bundle_id: str):
+        """
+        Create a PromotionalOfferV2SignatureCreator
+
+        :param signing_key: Your private key downloaded from App Store Connect
+        :param key_id: Your private key ID from App Store Connect
+        :param issuer_id: Your issuer ID from the Keys page in App Store Connect
+        :param bundle_id: Your app's bundle ID
+        """
+        super().__init__(audience="promotional-offer", signing_key=signing_key, key_id=key_id, issuer_id=issuer_id, bundle_id=bundle_id)
+
+    def create_signature(self, product_id: str, offer_identifier: str, transaction_id: Optional[str]) -> str:
+        """
+        Create a promotional offer V2 signature.
+        https://developer.apple.com/documentation/storekit/generating-jws-to-sign-app-store-requests
+        
+        :param product_id: The unique identifier of the product
+        :param offer_identifier: The promotional offer identifier that you set up in App Store Connect
+        :param transaction_id: The unique identifier of any transaction that belongs to the customer. You can use the customer's appTransactionId, even for customers who haven't made any In-App Purchases in your app. This field is optional, but recommended.
+        :return: The signed JWS.
+        """
+        if product_id is None:
+            raise ValueError("product_id cannot be null")
+        if offer_identifier is None:
+            raise ValueError("offer_identifier cannot be null")
+        feature_specific_claims = {
+            "productId": product_id,
+            "offerIdentifier": offer_identifier
+        }
+        if transaction_id is not None:
+            feature_specific_claims["transactionId"] = transaction_id
+        return self._create_signature(feature_specific_claims=feature_specific_claims)
+    
+class IntroductoryOfferEligibilitySignatureCreator(JWSSignatureCreator):
+    def __init__(self, signing_key: bytes, key_id: str, issuer_id: str, bundle_id: str):
+        """
+        Create an IntroductoryOfferEligibilitySignatureCreator
+
+        :param signing_key: Your private key downloaded from App Store Connect
+        :param key_id: Your private key ID from App Store Connect
+        :param issuer_id: Your issuer ID from the Keys page in App Store Connect
+        :param bundle_id: Your app's bundle ID
+        """
+        super().__init__(audience="introductory-offer-eligibility", signing_key=signing_key, key_id=key_id, issuer_id=issuer_id, bundle_id=bundle_id)
+
+    def create_signature(self, product_id: str, allow_introductory_offer: bool, transaction_id: str) -> str:
+        """
+        Create an introductory offer eligibility signature.
+        https://developer.apple.com/documentation/storekit/generating-jws-to-sign-app-store-requests
+        
+        :param product_id: The unique identifier of the product
+        :param allow_introductory_offer: A boolean value that determines whether the customer is eligible for an introductory offer
+        :param transaction_id: The unique identifier of any transaction that belongs to the customer. You can use the customer's appTransactionId, even for customers who haven't made any In-App Purchases in your app.
+        :return: The signed JWS.
+        """
+        if product_id is None:
+            raise ValueError("product_id cannot be null")
+        if allow_introductory_offer is None:
+            raise ValueError("allow_introductory_offer cannot be null")
+        if transaction_id is None:
+            raise ValueError("transaction_id cannot be null")
+        feature_specific_claims = {
+            "productId": product_id,
+            "allowIntroductoryOffer": allow_introductory_offer,
+            "transactionId": transaction_id
+        }
+        return self._create_signature(feature_specific_claims=feature_specific_claims)
+    
+class AdvancedCommerceAPIInAppSignatureCreator(JWSSignatureCreator):
+    def __init__(self, signing_key: bytes, key_id: str, issuer_id: str, bundle_id: str):
+        """
+        Create an AdvancedCommerceAPIInAppSignatureCreator
+
+        :param signing_key: Your private key downloaded from App Store Connect
+        :param key_id: Your private key ID from App Store Connect
+        :param issuer_id: Your issuer ID from the Keys page in App Store Connect
+        :param bundle_id: Your app's bundle ID
+        """
+        super().__init__(audience="advanced-commerce-api", signing_key=signing_key, key_id=key_id, issuer_id=issuer_id, bundle_id=bundle_id)
+
+    def create_signature(self, advanced_commerce_in_app_request: AdvancedCommerceAPIInAppRequest) -> str:
+        """
+        Create an Advanced Commerce in-app signed request.
+        https://developer.apple.com/documentation/storekit/generating-jws-to-sign-app-store-requests
+        
+        :param advanced_commerce_in_app_request: The request to be signed.
+        :return: The signed JWS.
+        """
+        if advanced_commerce_in_app_request is None:
+            raise ValueError("advanced_commerce_in_app_request cannot be null")
+        c = _get_cattrs_converter(type(advanced_commerce_in_app_request))
+        request = c.unstructure(advanced_commerce_in_app_request)
+        encoded_request = base64.b64encode(json.dumps(request).encode(encoding='utf-8')).decode('utf-8')
+        feature_specific_claims = {
+            "request": encoded_request
+        }
+        return self._create_signature(feature_specific_claims=feature_specific_claims)
\ No newline at end of file
diff --git a/appstoreserverlibrary/models/AppTransaction.py b/appstoreserverlibrary/models/AppTransaction.py
index 7093a100..6d2c98c3 100644
--- a/appstoreserverlibrary/models/AppTransaction.py
+++ b/appstoreserverlibrary/models/AppTransaction.py
@@ -7,6 +7,7 @@
 from .LibraryUtility import AttrsRawValueAware
 
 from .Environment import Environment
+from .PurchasePlatform import PurchasePlatform
 
 @define
 class AppTransaction(AttrsRawValueAware):
@@ -96,4 +97,23 @@ class AppTransaction(AttrsRawValueAware):
     The date the customer placed an order for the app before it's available in the App Store.
     
     https://developer.apple.com/documentation/storekit/apptransaction/4013175-preorderdate
+    """
+
+    appTransactionId: Optional[str] = attr.ib(default=None)
+    """
+    The unique identifier of the app download transaction.
+    
+    https://developer.apple.com/documentation/storekit/apptransaction/apptransactionid
+    """
+
+    originalPlatform: Optional[PurchasePlatform] = PurchasePlatform.create_main_attr('rawOriginalPlatform')
+    """
+    The platform on which the customer originally purchased the app.
+    
+    https://developer.apple.com/documentation/storekit/apptransaction/originalplatform-4mogz
+    """
+
+    rawOriginalPlatform: Optional[str] = PurchasePlatform.create_raw_attr('originalPlatform')
+    """
+    See originalPlatform
     """
\ No newline at end of file
diff --git a/appstoreserverlibrary/models/JWSRenewalInfoDecodedPayload.py b/appstoreserverlibrary/models/JWSRenewalInfoDecodedPayload.py
index 58c5d734..8a2d9ca6 100644
--- a/appstoreserverlibrary/models/JWSRenewalInfoDecodedPayload.py
+++ b/appstoreserverlibrary/models/JWSRenewalInfoDecodedPayload.py
@@ -174,4 +174,25 @@ class JWSRenewalInfoDecodedPayload(AttrsRawValueAware):
     An array of win-back offer identifiers that a customer is eligible to redeem, which sorts the identifiers to present the better offers first.
     
     https://developer.apple.com/documentation/appstoreserverapi/eligiblewinbackofferids
+    """
+
+    appAccountToken: Optional[str] = attr.ib(default=None)
+    """
+    The UUID that an app optionally generates to map a customer's in-app purchase with its resulting App Store transaction.
+    
+    https://developer.apple.com/documentation/appstoreserverapi/appaccounttoken
+    """
+
+    appTransactionId: Optional[str] = attr.ib(default=None)
+    """
+    The unique identifier of the app download transaction.
+    
+    https://developer.apple.com/documentation/appstoreserverapi/appTransactionId
+    """
+
+    offerPeriod: Optional[str] = attr.ib(default=None)
+    """
+    The duration of the offer.
+    
+    https://developer.apple.com/documentation/appstoreserverapi/offerPeriod
     """
\ No newline at end of file
diff --git a/appstoreserverlibrary/models/JWSTransactionDecodedPayload.py b/appstoreserverlibrary/models/JWSTransactionDecodedPayload.py
index b990b6f3..38fd0a6f 100644
--- a/appstoreserverlibrary/models/JWSTransactionDecodedPayload.py
+++ b/appstoreserverlibrary/models/JWSTransactionDecodedPayload.py
@@ -237,4 +237,18 @@ class JWSTransactionDecodedPayload(AttrsRawValueAware):
     rawOfferDiscountType: Optional[str] = OfferDiscountType.create_raw_attr('offerDiscountType')
     """
     See offerDiscountType
+    """
+
+    appTransactionId: Optional[str] = attr.ib(default=None)
+    """
+    The unique identifier of the app download transaction.
+    
+    https://developer.apple.com/documentation/appstoreserverapi/appTransactionId
+    """
+
+    offerPeriod: Optional[str] = attr.ib(default=None)
+    """
+    The duration of the offer.
+    
+    https://developer.apple.com/documentation/appstoreserverapi/offerPeriod
     """
\ No newline at end of file
diff --git a/appstoreserverlibrary/models/PurchasePlatform.py b/appstoreserverlibrary/models/PurchasePlatform.py
new file mode 100644
index 00000000..9549c040
--- /dev/null
+++ b/appstoreserverlibrary/models/PurchasePlatform.py
@@ -0,0 +1,16 @@
+# Copyright (c) 2025 Apple Inc. Licensed under MIT License.
+
+from enum import Enum
+
+from .LibraryUtility import AppStoreServerLibraryEnumMeta
+
+class PurchasePlatform(str, Enum, metaclass=AppStoreServerLibraryEnumMeta):
+    """
+    Values that represent Apple platforms.
+    
+    https://developer.apple.com/documentation/storekit/appstore/platform
+    """
+    IOS = "iOS"
+    MAC_OS = "macOS"
+    TV_OS = "tvOS"
+    VISION_OS = "visionOS"
diff --git a/tests/resources/models/appTransaction.json b/tests/resources/models/appTransaction.json
index b3b937b8..9313c31c 100644
--- a/tests/resources/models/appTransaction.json
+++ b/tests/resources/models/appTransaction.json
@@ -9,5 +9,7 @@
   "originalApplicationVersion": "1.1.2",
   "deviceVerification": "device_verification_value",
   "deviceVerificationNonce": "48ccfa42-7431-4f22-9908-7e88983e105a",
-  "preorderDate": 1698148700000
+  "preorderDate": 1698148700000,
+  "appTransactionId": "71134",
+  "originalPlatform": "iOS"
 }
\ No newline at end of file
diff --git a/tests/resources/models/signedRenewalInfo.json b/tests/resources/models/signedRenewalInfo.json
index 30b90d27..d4bf60be 100644
--- a/tests/resources/models/signedRenewalInfo.json
+++ b/tests/resources/models/signedRenewalInfo.json
@@ -19,5 +19,8 @@
   "eligibleWinBackOfferIds": [
     "eligible1",
     "eligible2"
-  ]
+  ],
+  "appTransactionId": "71134",
+  "offerPeriod": "P1Y",
+  "appAccountToken": "7e3fb20b-4cdb-47cc-936d-99d65f608138"
 }
diff --git a/tests/resources/models/signedTransaction.json b/tests/resources/models/signedTransaction.json
index 0211857b..f81bac8c 100644
--- a/tests/resources/models/signedTransaction.json
+++ b/tests/resources/models/signedTransaction.json
@@ -24,5 +24,7 @@
   "storefrontId":"143441",
   "price": 10990,
   "currency": "USD",
-  "offerDiscountType": "PAY_AS_YOU_GO"
+  "offerDiscountType": "PAY_AS_YOU_GO",
+  "appTransactionId": "71134",
+  "offerPeriod": "P1Y"
 }
\ No newline at end of file
diff --git a/tests/test_decoded_payloads.py b/tests/test_decoded_payloads.py
index aaea38ce..44709c47 100644
--- a/tests/test_decoded_payloads.py
+++ b/tests/test_decoded_payloads.py
@@ -11,6 +11,7 @@
 from appstoreserverlibrary.models.OfferDiscountType import OfferDiscountType
 from appstoreserverlibrary.models.OfferType import OfferType
 from appstoreserverlibrary.models.PriceIncreaseStatus import PriceIncreaseStatus
+from appstoreserverlibrary.models.PurchasePlatform import PurchasePlatform
 from appstoreserverlibrary.models.RevocationReason import RevocationReason
 from appstoreserverlibrary.models.Status import Status
 from appstoreserverlibrary.models.Subtype import Subtype
@@ -38,6 +39,9 @@ def test_app_transaction_decoding(self):
         self.assertEqual("device_verification_value", app_transaction.deviceVerification)
         self.assertEqual("48ccfa42-7431-4f22-9908-7e88983e105a", app_transaction.deviceVerificationNonce)
         self.assertEqual(1698148700000, app_transaction.preorderDate)
+        self.assertEqual("71134", app_transaction.appTransactionId)
+        self.assertEqual(PurchasePlatform.IOS, app_transaction.originalPlatform)
+        self.assertEqual("iOS", app_transaction.rawOriginalPlatform)
 
     def test_transaction_decoding(self):
         signed_transaction = create_signed_data_from_json('tests/resources/models/signedTransaction.json')
@@ -79,6 +83,8 @@ def test_transaction_decoding(self):
         self.assertEqual("USD", transaction.currency)
         self.assertEqual(OfferDiscountType.PAY_AS_YOU_GO, transaction.offerDiscountType)
         self.assertEqual("PAY_AS_YOU_GO", transaction.rawOfferDiscountType)
+        self.assertEqual("71134", transaction.appTransactionId)
+        self.assertEqual("P1Y", transaction.offerPeriod)
 
     
     def test_renewal_info_decoding(self):
@@ -112,6 +118,9 @@ def test_renewal_info_decoding(self):
         self.assertEqual(OfferDiscountType.PAY_AS_YOU_GO, renewal_info.offerDiscountType)
         self.assertEqual("PAY_AS_YOU_GO", renewal_info.rawOfferDiscountType)
         self.assertEqual(['eligible1', 'eligible2'], renewal_info.eligibleWinBackOfferIds)
+        self.assertEqual("71134", renewal_info.appTransactionId)
+        self.assertEqual("P1Y", renewal_info.offerPeriod)
+        self.assertEqual("7e3fb20b-4cdb-47cc-936d-99d65f608138", renewal_info.appAccountToken)
 
     def test_notification_decoding(self):
         signed_notification = create_signed_data_from_json('tests/resources/models/signedNotification.json')
diff --git a/tests/test_jws_signature_creator.py b/tests/test_jws_signature_creator.py
new file mode 100644
index 00000000..857c83a3
--- /dev/null
+++ b/tests/test_jws_signature_creator.py
@@ -0,0 +1,128 @@
+# Copyright (c) 2025 Apple Inc. Licensed under MIT License.
+
+from attr import define
+import attr
+import base64
+import json
+import jwt
+import unittest
+from appstoreserverlibrary.jws_signature_creator import AdvancedCommerceAPIInAppRequest, AdvancedCommerceAPIInAppSignatureCreator, IntroductoryOfferEligibilitySignatureCreator, PromotionalOfferV2SignatureCreator
+from tests.util import read_data_from_binary_file
+
+@define
+class TestInAppRequest(AdvancedCommerceAPIInAppRequest):
+    test_value: str
+
+class JWSSignatureCreatorTest(unittest.TestCase):
+    def test_promotional_offer_signature_creator(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = PromotionalOfferV2SignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        signature = signature_creator.create_signature("productId", "offerIdentifier", "transactionId")
+        self.assertIsNotNone(signature)
+        headers = jwt.get_unverified_header(signature)
+        payload = jwt.decode(signature, options={"verify_signature": False})
+
+        # Header
+        self.assertEqual("JWT", headers["typ"])
+        self.assertEqual("ES256", headers["alg"])
+        self.assertEqual("keyId", headers["kid"])
+        # Payload
+        self.assertEqual("issuerId", payload['iss'])
+        self.assertIsNotNone(payload['iat'])
+        self.assertFalse('exp' in payload)
+        self.assertEqual("promotional-offer", payload['aud'])
+        self.assertEqual('bundleId', payload['bid'])
+        self.assertIsNotNone(payload['nonce'])
+        self.assertEqual('productId', payload['productId'])
+        self.assertEqual('offerIdentifier', payload['offerIdentifier'])
+        self.assertEqual('transactionId', payload['transactionId'])
+
+    def test_promotional_offer_signature_creator_transaction_id_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = PromotionalOfferV2SignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        signature = signature_creator.create_signature("productId", "offerIdentifier", None)
+        payload = jwt.decode(signature, options={"verify_signature": False})
+        self.assertFalse('transactionId' in payload)
+
+    def test_promotional_offer_signature_creator_offer_identifier_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = PromotionalOfferV2SignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        with self.assertRaises(ValueError):
+            signature_creator.create_signature("productId", None, "transactionId")
+
+    def test_promotional_offer_signature_creator_product_id_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = PromotionalOfferV2SignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        with self.assertRaises(ValueError):
+            signature_creator.create_signature(None, "offerIdentifier", "transactionId")
+    
+    def test_introductory_offer_eligibility_signature_creator(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = IntroductoryOfferEligibilitySignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        signature = signature_creator.create_signature("productId", True, "transactionId")
+        self.assertIsNotNone(signature)
+        headers = jwt.get_unverified_header(signature)
+        payload = jwt.decode(signature, options={"verify_signature": False})
+
+        # Header
+        self.assertEqual("JWT", headers["typ"])
+        self.assertEqual("ES256", headers["alg"])
+        self.assertEqual("keyId", headers["kid"])
+        # Payload
+        self.assertEqual("issuerId", payload['iss'])
+        self.assertIsNotNone(payload['iat'])
+        self.assertFalse('exp' in payload)
+        self.assertEqual("introductory-offer-eligibility", payload['aud'])
+        self.assertEqual('bundleId', payload['bid'])
+        self.assertIsNotNone(payload['nonce'])
+        self.assertEqual('productId', payload['productId'])
+        self.assertEqual(True, payload['allowIntroductoryOffer'])
+        self.assertEqual('transactionId', payload['transactionId'])
+
+    def test_introductory_offer_eligibility_signature_creator_transaction_id_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = IntroductoryOfferEligibilitySignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        with self.assertRaises(ValueError):
+            signature_creator.create_signature("productId", True, None)
+    
+    def test_introductory_offer_eligibility_signature_creator_allow_introductory_offer_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = IntroductoryOfferEligibilitySignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        with self.assertRaises(ValueError):
+            signature_creator.create_signature("productId", None, "transactionId")
+
+    def test_introductory_offer_eligibility_signature_creator_product_id_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = IntroductoryOfferEligibilitySignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        with self.assertRaises(ValueError):
+            signature_creator.create_signature(None, True, "transactionId")
+
+    def test_advanced_commerce_api_in_app_signature_creator(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = AdvancedCommerceAPIInAppSignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        request = TestInAppRequest("testValue")
+        signature = signature_creator.create_signature(request)
+        self.assertIsNotNone(signature)
+        headers = jwt.get_unverified_header(signature)
+        payload = jwt.decode(signature, options={"verify_signature": False})
+
+        # Header
+        self.assertEqual("JWT", headers["typ"])
+        self.assertEqual("ES256", headers["alg"])
+        self.assertEqual("keyId", headers["kid"])
+        # Payload
+        self.assertEqual("issuerId", payload['iss'])
+        self.assertIsNotNone(payload['iat'])
+        self.assertFalse('exp' in payload)
+        self.assertEqual("advanced-commerce-api", payload['aud'])
+        self.assertEqual('bundleId', payload['bid'])
+        self.assertIsNotNone(payload['nonce'])
+        request = payload['request']
+        decode_json = json.loads(str(base64.b64decode(request).decode('utf-8')))
+        self.assertEqual('testValue', decode_json['test_value'])
+
+    def test_advanced_commerce_api_in_app_signature_creator_request_missing(self):
+        signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
+        signature_creator = AdvancedCommerceAPIInAppSignatureCreator(signing_key, 'keyId', 'issuerId', 'bundleId')
+        with self.assertRaises(ValueError):
+            signature_creator.create_signature(None)
\ No newline at end of file
diff --git a/tests/test_promotional_offer_signature_creator.py b/tests/test_promotional_offer_signature_creator.py
index 31cdb845..3b73310a 100644
--- a/tests/test_promotional_offer_signature_creator.py
+++ b/tests/test_promotional_offer_signature_creator.py
@@ -11,5 +11,5 @@ class PromotionalOfferSignatureCreatorTest(unittest.TestCase):
     def test_signature_creator(self):
         signing_key = read_data_from_binary_file('tests/resources/certs/testSigningKey.p8')
         signature_creator = PromotionalOfferSignatureCreator(signing_key, 'keyId', 'bundleId')
-        signature = signature_creator.create_signature("productId", "offerId", "applicationUsername", UUID("20fba8a0-2b80-4a7d-a17f-85c1854727f8"), 1698148900000)
+        signature = signature_creator.create_signature("productId", "offerId", "appAccountToken", UUID("20fba8a0-2b80-4a7d-a17f-85c1854727f8"), 1698148900000)
         self.assertIsNotNone(signature)
\ No newline at end of file