Minecraft Dungeons ii deluxe download locked to single account

The deluxe download code only works for one account on the same counsel. My 9 year old son bought game with his own money. I installed game and used download code for deluxe extras…and it only is for MY ACCOUNT!? That is a bug or an incredibly terrible moneygrab. Please fix asap or tell me how to transfer this damn deluxe download to his account.