Apple+ and credit card

I'm entitled to a free year of Apple+ with a purchase I recently made but my 2018 LG TV does not support the app and to watch through my MacBook Pro I have to give it credit card details first. I don't have, or want, a credit card, and my debit card isn't accepted. So what should be free is actually unaccessible. Is there something I'm missing?

And almost as annoying, there isn't an 'Apple+' topic to select to post this question. 😑