All digital xbox free codes not working

My friend recently got a new xbox all digital edition, and it came with free codes for sea of thieves and fortnite spider night. He gave me the fortnite code as he does not play fortnite. I tried to pit in the code, and it said that the code had already
been redeemed. Neither me or my friend used the code and the sea of thieves one didnt work either!

(I know that the xbox all digital was discontinued, but his mom gave him a new one that was never opened for his birthday, and none of the codes worked)

Thanks for any help that you can give!

:)