Who has bought the game, he has to sign in

What is the game in question?

Are you sure you purchased it via the account your signed in with ?

Have you downloaded the correct version for the game you bought?

For eg CoD BO : cold war has 2 versions: an xbox one and a xbox series x version.

But it is possible to play the xbox one version on the series x via backward compatibility.

you need to have the old account to make the xbox the home console for that account to play on your other account, nobody here can help get your old info, if you cannot remember then you may need to contact support, but be prepared to answer a lot of questions to prove ownership of the account.

Hello Keely,

Thank you for posting in the Microsoft Community.

I'm sorry to hear that your husband has lost his games after setting up a new account. To restore his games, he will need to sign in with the original account that he used to purchase them. Then, he can go to My Games and Apps, select Full Library, and choose All Owned Games. From there, he can download the games that he has bought, such as Modern Warfare 3. If he has any trouble signing in with his original account, please let us know.

Thank you for choosing Xbox and have a great day.

Hi!

We haven't heard from you, so we assume that your issue has already been addressed. We will not be monitoring this thread moving forward so, if you need further assistance, please create a new thread to discuss these concerns by clicking this link: https://answers.microsoft.com/en-us/newthread?threadtype=Questions&cancelurl=%2Fen-us

Thank you for understanding.

The Home setting is the only way to share the games. Otherwise, the person who bought the games has to be signed in.