Did you get this sorted out ?
Out of curiosity are you a Republic of Ireland customer and either just purchased a NowTV Pass or started a 7 day trial.
Where i have just found out that since December 2020 NowTV have started a secure payment system for Republic of Ireland customers where an unique code is sent to your phone and you need to enter this code on the NowTV online checkout page when you buy the pass or begin a 7 day trial.
Don't know how it fully works because i am a UK customer and haven't seen this new NowTV system working in practice.
If you are a UK customer and still stuck, come back with some further information and i will either try to help further (if i can) or give you a link to contact NowTV directly for further assistance & help.
See if the code from your television screen works by typing the code into this link page below.
If no joy, then see if using a different internet browser with your iPad makes any difference.
Also note, from memory the activation code on the television screen refreshes to a new code after about 9 or 10 minutes.