My bro gifted me the game recently, and my free period is about to end. So for my birthday he gifted me a subscription to it. But the code won't work. We also had this problem when he gifted me the game itself. Turned out Amazon sent him the wrong code. I'm worried this has happened again.

To double check, where do you input the code for a gift subscription? I've been trying in the Enter Item Code section, since it's the only place I can find for codes.