There are several possible reasons you might be experiencing issues. So let’s start with a few basic steps. I’ve added links to support articles that may offer solutions to issues you might encounter.
You just need to double check most of the settings below. Please make sure your iOS is updated to 17.4 and perform the forced restart. A forced restart is much more than just turning the iPhone off and on.
Confirm your region is set correctly.
Change the language and region on iPhone - Apple Support
Change your Apple ID country or region
If you’ve confirmed the above, please update your iPhone to the latest iOS, 17.3 or higher. Older iPhones may only support 15.7.5, but Apple Pay will function.
Update iOS on iPhone - Apple Support
Once updated, please do a forced restart of your iPhone.
Force restart iPhone - Apple Support
Make sure your are signed into your Apple ID/iCloud account on your iPhone.
Sign out of iCloud on your iPhone, iPad, Apple TV, or Mac - Apple Support
Follow the steps in this support article for adding credit/debit cards to your Wallet.
Set up Apple Pay - Apple Support