With Digital Direct, no codes are required. All digital content including games, subscriptions, and exclusive content will be redeemed to your Microsoft account and directly delivered to your Xbox console during setup.
Redeem offers at setup
During the Setup Process for your new console, the content and service offers attached to the console will appear to redeem. Click “Claim it” to redeem each item. Once redeemed, your content can be found in your digital library under My Games & Apps.
You can also redeem any item at a later date if you so choose.
Disclaimer: All included digital content will be attached to the first Microsoft Account that redeems it.
Redeem in Accounts
Select Settings > Account > Included with this Xbox to see an overview of and redemption status of any Digital Direct offers included with your console.
Redeem in My Library
Press the Xbox button to open the guide, and then select My games & apps > Full Library > Console offers to see your offers.
Source: Xbox