Xbox one store game code

from your console check that the game appears as available for download or from a pc, in the option of "my games" there must appear the game linked to your account in case it does not appear means that the code was changed by someone else or I breathe

if its from a key site many have a "sheild" that protects customers from fake codes you will have to contact them to recover your money if it was from a store or legitimate site then contact there customer support and they should give you a new code

hope this helped

did u buy it from a store? or one of them websites that sell codes

Where did you buy it? That is the main question.

First check to see if it’s been added to your library anyway, after that you need to contact support

https://beta.support.xbox.com/contact-us