I can not add my bank account in apple card

Did you already go here - How to make Apple Card payments - Apple Support

Is this where you are getting suck?

Add a bank account

1. Get your bank account number and bank routing number.
2. Open Wallet on your iPhone and tap Apple Card.
3. Tap the more button .
4. Scroll down and tap Bank Accounts.
5. Tap Add a Bank Account, then follow the instructions on your screen.

You can add multiple bank accounts to make payments. The first bank account you add will be your default bank account.

Do you already have a debit card from that bank in your Apple ID payment methods or in Wallet?

I’m having the same problem. Can’t add bank account and routing info. Works for Apple Cash card but not Apple Card.

Read in another thread about the routing number and that worked. Cryptic error message tho