To play on Xbox, follow the instructions below:
1) Sign in to your Xbox LIVE account.
2) Press the silver/green Xbox Guide Button on the controller
3) Navigate to Games & Apps tab tab.
4) Select Redeem Code & enter code.
To play on Windows 10, follow the instructions below:
1) On your Windows 10 device, find and open Microsoft Store:
2) Make sure you are logged in to your Microsoft account
3) Once logged in, search for the purchased game
4) Click on the three dots next to the Buy Now button then redeem the provided code to activate and download the game.