Transferring a purchased minecraft license to a family member / child

This is not possible if you buy it once in one account so it is assigned to it and you can not transfer the game to another account.

To add to denis97g's post, game progress can not be transferred either.

You can not transfer items between accounts unfortunately but you can use the My Home Xbox feature, that when set, allows other accounts on your console to share games and gold of other accounts. Please note that some downloadable content/extras can't be
shared, though.

1. Log in in the account that owns the game (in this case, minecraft).

2. Press the Xbox button to open the guide.

3. Select System > Settings > Personalization, and then select
My home Xbox.

4. Select Make this my home Xbox to designate the console as your home Xbox.

5. Log in on the other account and it can access and play minecraft.

More info:
https://support.xbox.com/xbox-one/games/my-home-xbox

Please note that you get 5 moves of this license per year.

Hello, you can't transfer it, but you can share it if you set your xbox as home https://support.xbox.com/en-US/games/game-setup/my-home-xbox

Points purchased on a non-family plan can not be transferred.

Family plan points can only be transferred after the plan is started and only from Parent to Child - Not in reverse.

You can move his profile to your xbox - make the purchases for the DLC - arcade games/game add-on's but no multi-player maps packs (i think) then you will be able to use them - until he does a license transfer.

You should call support to see if there is anything they can do for you.