Online:

• If you have an account on Xbox Live simply log in to your account on https://redeem.microsoft.com, and enter the 25-digit code.
• If you need to get an account - Go to live.xbox.com and follow the steps to create a new account. Then go to https://redeem.microsoft.com, and enter the 25-digit code. 

 For Xbox One / Xbox Series X|S products:

• From the Home screen, scroll right to Store.
• Under Games, select Browse All Games
• Select Use a code. Or, say “Xbox, use code.” (if you have Kinect)
• If prompted, sign in and select Enter the 25-character code.
• Use the onscreen keyboard to enter your 25-character code. Don’t worry about hyphens, the system takes care of those for you.
• Once your code is redeemed, you’ll receive a confirmation message.