Apple Pay countryCode

I have read the documentation and it is not clear on this point. It says,

https://developer.apple.com/library/archive/ApplePay_Guide/CreateRequest.html#//apple_ref/doc/uid/TP40014764-CH3-SW2

'The payment request’s country code indicates the country where the purchase took place or where the purchase will be processed. Use a two-character ISO country code, such as

US
.'


For Apple Pay on the Web, should the countryCode used be the country where the acquiring merchant bank account is, the country where the servers are, or the country where the customer's browser is, or is it some other consideration?


We currently specify US as that is the country where we are writing the code. However, overseas stores using this code are getting declines and their merchant accounts are in fact not in the US.


Fixing this to be configurable by merchant is simple but we do not want to waste time on it if it is not even a likely cause of the issue.