How do use my American Express card to make any payment without any issues
Why do I keep having problems whith my iPhone in order to make any kind of payments that I feel like it
iPhone 15 Pro Max, iOS 17
Without knowing what problems you're having, it's hard to say how to resolve them.
I've been using an American Express card as my default payment option for my Apple ID since... well, since adding a payment option to an Apple ID became an option. I've never had a problem.