Hi Simao Silva,
during an unsuccessful attempt to get your renewer working, I noticed that the renew.py is searching for a button with the exact test "confirm" in the hosts list. This only is the case if the language is set to English in the No-IP settings.
After I changed to English language in my personal settings on No-IP homepage, your renewer worked like a charm.
As there might be more people running into the same issue, it might be worth mentioning this in the readme.
BTW: Excellent tool!
BR
Ralf