Hi @Anonymous User
Over on NOW Twitter in the last couple of days people using an iOS Mobile device either iOS 11 or 12 have reported the NOW App doesn't work anymore and stopped working this week and according to this NOW article linked below it's been unsupported for quite a while now.
https://help.nowtv.com/article/installing-now-on-ios-tablet-mobile
If you can't update to iOS13 which I am guessing you can't by asking the question on here I don't think there is much you can do with regards to watching NOW on your older Apple iPad (unless somebody has figured out some sort of workaround).
You could email NOW using the address in the screenshot below, but I doubt they will be able to offer any advice using your older iPad with the NOW App and over on Twitter they are only suggesting using other playback devices.
