Wallet app not working: Unable to add ATM card on iPhone

Does your ATM card display a Mastercard or Visa logo? If so, it’s a debit card, not an ATM card, and it may be added if the issuing bank supports electronic wallets and Apple Pay.

If the card does not display a payment network logo, it is not an ATM card, and as such does not support electronic wallets and Apple Pay.

Did you follow the steps in this article to set up Apple Pay?

Add cards for Apple Pay - Apple Support

Does your banking institution support Apple Pay?

Places that support Apple Pay - Apple Support