Hi Dionysus0169,
Welcome to the Apple Community.
You may need to use the method below to add credit or debit cards to Wallet:
Apple support's article: Set up Apple Pay - Apple Support
says:
Add a new card on your iPhone
✽ In the Wallet app, tap the Add button (+)
✽ Tap Debit or Credit Card.
✽ Tap Continue.
✽ Follow the steps on the screen to add a new card.
If prompted, choose your bank or card issuer from the list or find them using the search bar.
✽ Verify your information with your bank or card issuer. They might ask you to provide additional information or to download an app before approving your card for use with Apple Pay.
All the best :-)