Yeah, that is true. I have asked about internal payments (in Apple account), not Apple Pay.
I also reached out to Wise with this problem, and we figured out that you don’t support cards issued from a different country/region, which is set in account settings.
In other words, I’m from Ukraine. I have set region Ukraine in my Apple account. Wise provided the card, which was issued in UK. So Apple declines to add this card to an Apple account.
The same problem is with Payoneer. It’s weird because, in fact, I registered an account in Wise, and they provided a card officially. I can use it everywhere. Including Netflix, Google, Apple Pay, but I can’t use that card in my Apple account.
Probably you need to change the politics for Ukraine that we can use cards issued from different countries. At least you should give the ability to add cards issued from UK and USA for Ukrainian users.