are you referring to in-app-payments (Games) or paying at point-of-sale with Google Pay?
IAP should work to some degree - Am I supposed to be able to use Google Play services for IAP? - #3 by tcecyk
Google Pay / Wallet functions have some coverage, but not fully functional - Contactless payments in store with /e/ phone - #3 by tcecyk
Ofc this all needs your own Google Account