How to redeem your Xbox Card 

1. Sign in to your Xbox console (make sure you’re signed in with the Microsoft account you want to redeem the code with).
2. From the Home screen, select and open the Store app. (If the Store app is not displayed, go to My games & apps, select Apps, and select the Store app from there.)
3. In the Store app, move the cursor left or press the View button  on the controller to open the side menu.
4. From that menu, select Redeem.
5. Enter the 25-character code, and then follow the prompts. Don’t worry about hyphens, the system takes care of those for you.