I can’t add my debit card as a payment method because it says they don’t recognize my bank

Start here -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

👉 fyi: Not all credit & debit cards seem to work with App Store / iTunes Store, try a different one, or preferably a credit card. If your card is not accepted as a paymenf method, you need to contact your bank.