You have purchased an account, not a key. This account belongs to you alone, and no one else has access to its details.
To get started,
*Add the purchased account to your console and set it as Xbox home account:
*Purchased account has to be added as a new user, not as a guest
*download the game and play it

*you can Change account data :
-Change the email
-Change the password
-Add 2FA