XBOX Live 14-day Gold Trial Membership

Press the Xbox button to open the guide, and then select Home. Make sure you’re signed in to the Microsoft account for which you want to redeem the code.
On the Home screen, scroll right and select the Microsoft Store icon.
Select Use a code.
Use the onscreen keyboard to enter your 25-character code on the Redeem your code or gift cardscreen, and then select Next to finalize your redemption. Don’t worry about hyphens, the system takes care of those for you.