If I have an Xbox game on disk am I able to download it for free?

Digital games can be shared via the "Home Xbox" feature or the Xbox family settings. Physical copies of games on disc have to be inserted into the console every time you want to play that game regardless of which console your account is on and so forth.
You have to download the game off of the disc and use that disc as a sort of license activation key whereas buying a game digitally will lock it to your account making your account the key to the game. To put it in layman's terms, you'd either need to buy
the game digitally on another account or your own and share that account with the family, or get another copy for the other Xbox if you wish to be able to play both at the same time.

Here's some link about the "Home Xbox" and Family Settings on console.

https://beta.support.xbox.com/help/hardware-network/console/my-home-xbox

https://support.xbox.com/en-US/browse/xbox-one/security/Family settings

Hello XboxOne2020,

Thank you for posting on the Xbox forums. As this question has been answered, we will be locking this thread. If you ever have another question or would like to start a discussion, don't hesitate to create a new thread.
We look forward to hearing more from you soon!

Hello XboxOne2020,

Thank you for posting on the Xbox forums. We understand that you are interested in learning if you can use the home console feature to share the license for an Xbox One disc. The

home console feature shares only games, subscriptions and some downloadable content. There is some content that developers do not allow to be shared. You would need to purchase another disc or the digital version of NBA2k20 in order to play it on both consoles.
Thank you again, and we look forward to hearing from you.

Hello, you will have to download it off the disk on both consoles, then you can play it on one console at a time as you only have one disk. So if you want the two children to play together but on different consoles you will have to buy 2 disks.

Thank you for your help. We will not be buying the disks anymore