How can I take my debit card off my iPhone
Need help removing my debit card from this device
iPhone 6s, iOS 13
You can't remove it if it is the only card on file and you have a subscription.
Log into your account in the App Store/iTunes and you should be able to change/verify it there. Or you can click the blue Edit payment methods in the article below. When signed in and the page loads, you will be on the credit card page. After updating that, click the Go Back button at the lower left and you will be on the address page. If you have a subscription, you need to add the new card, and then promote it to the primary payment method before you can remove the old card.
Apple ID payment information - change.
Also see.
Apple ID without a credit card
Apple ID - If you can‘t choose None when you edit your Apple ID payment information.