I Bought it and it never worked for me , xbox kept asking me to add some sort of payment method. And not with the price increase i just cant be bothered , so here goes , just lemme know if it works sp at least i know my source is good.
country USA
QFTMG-7MF3K-VDW23-9T2PG-H3YT

add the last letter of the alphabet at the end to complete the code

I try to redeem it on https://account.microsoft.com/billing/redeem but it says

"Check the instructions that came with your code. You might need to redeem it on a different web page or device, or you may be ineligible to redeem this code."

Here is a free xbox pc game pass i got from my dc subscription

GDH6T-K6JQ2-VKJD9-7X6V6-GR9TZ Idk whats it for I think its for a 1 month game pass or smth

The date is 15th May 2025 and in the past I used Nord VPN to redeem Xbox game pass ultimate (India) codes from Eneba and it worked for an Australian console gamer like me. Now I'm reading about that Microsoft have made several changes to this kind of method.

Since I'm unable to find definitive answers online, I'm asking here for current methods of getting it to work on existing accounts. What region and VPN's can it work.