Payment Request API - it should be mentioned that dom.payments.request.supportedRegions should contain your country

[ashucg]

I was trying the API and window.PaymentRequest was returning undefined, but thanks to caniuse I came to know about dom.payments.request.supportedRegions config and on adding my country's code, i.e., IN, PaymentRequest finally worked.

I believe that it must be mentioned on MDN as well, because if I am using MDN, I am expecting it to contain all the information I need to try new APIs

[ddbeck]

Huh, this is an interesting issue! I looked into it and bug 1501102 seems to show that before Firefox 65 the only supported region was California. We probably need to document the pref on 65+ and add a note for the existing 55 entry.

[queengooborg]

Closing this as #3096 seems to have already added the supportedRegions preference.