Are Windows coupons good worldwide

[Schnuffi]

Ok its like this I live in Germany but my native language is English (from Canada)
So I like my apps in English and so to have Cortona to work in English I have the region set on my phone to the US. But if I want to purchase an app for me to pay for the app using my carrier does not work unless I change the region back to Germany. I don't want to use my Visa for such things. So if I buy a windows store coupon in Germany can I use the coupon to buy apps from the US store?

 

[Chintan Gohel]

tried searching online but couldn't find anything
I'm thinking it might not work but only way to check would be to to try it out or talk with their chat support