+VOUCH and BUMP for this guy here.
I couldn't find any other seller for YT Premium.
I then asked a lot of questions, because of seeing them for the 1st time here. They answered all super well.
If you want to buy an upgrade for YT, get it from them! Friendly people to be working with!
You can also use their service anywhere in the world, even if your country doesn't support Youtube Premium.
Tested myself and it works