How can you update a credit/debit card in apple pay?

Hi, es2conn.

Apple Pay uses the payment methods that you have added to Wallet on your device. If you just need to update the billing address, you should be able to follow these instructions:

1. Open Wallet
2. Tap the card you need to update
3. Tap the More "..." button on the top right
4. Tap your name in Billing Address near the bottom
5. Tap Edit
6. Update your information
7. Tap Done

If you need to make other adjustments, like correcting the card number or expiration date, you may need to remove and add it again.

This article has more information about using Apple Pay

Set up Apple Pay - Apple Support

Cheers.