Error
I could not set up Apple Pay on my IPad. It was saying a message.
iPad, iPadOS 14
Are you in a supported country or region?
Settings > General > Language & Region, then scroll to Region.
Are you running the latest version of iOS? This is currently version iOS 14.6 (This could help fix your issue)
Settings > General > About
You might also want to try removing the card from your wallet and trying again, or if all else fails contact your card issuer / bank for help.