Apple Pay restricted

For you payment method, contact your bank to find out why its getting declined.

Currently adding the Apple account to wallet is apparently only supported in the US and maybe Canada. It will appear as a possibility elsewhere, but trying to add it will issue and error every time. Nothing to do there, but wait for Apple to fix that.

If you mean Apple Cash rather than Apple Pay, (they are 2 very different things) then follow the steps in the support document you posted from. It tells you exactly what you need to do.

If you do mean Apple Pay, then explain what is happening exactly, because Apple Pay cannot normally be restricted