Apple Pay is not working on iPhone 14

Make sure your iPhone's country & region is set correctly locally on the device.

After that, probably call AppleCare and get them to run diagnostics on your device to see if anything is amiss with the internal components that handle Apple Pay (RFID stuff) for a potential underlying hardware issue.

Otherwise, you'll probably end up calling Apple Wallet / Apple Pay support to have that looked into in finer detail.

If you are trying to add a credit or debit card you should be able to click on the + sign and add it. If you are trying to add a different kind of card you have to use an app from the issuer of the card to add it.

What card are you trying to add?