a donor has run into errors using ApplePay with their Amex card and claims it's due to configuration our end, and said the issue is similar to this one. https://www.reddit.com/r/ApplePay/comments/g121kt/why_is_one_of_my_apple_pay_cards_not_available/. From donor: It’s an ApplePay misconfiguration at Wiki. Amex not configured. Picture of error when I try to donate (second screen after clicking on choose card - I do not use Apple Cash):"

I have raised this with Adyen to see what they can tell me, but I am putting this task out here in case it comes back to something we could control.