no option to add credit card in wallet

The problem is that when opening wallet, there is only 'passes' showing and a plus sign for them, and options to scan codes etc.

There is no option to add a credit card to setup apple pay with my compliant credit card.

I've tried

- checking region UK (OK), changing to US and back to UK

- making sure I'm connected to iCloud.

- turning passcode off and opening wallet- but not asked to reinstate passcode, so went back to re-set it anyway (was 4 digits re-set required 6).

- double clicking the button and swiping up to switch off all apps, then force quitting and re-starting

Still I've got no option to add a card.

Perhaps if I could go back through a setup I could configure it differently- but how can I get back to that setup?

Or other ideas please?

Thanks