Late question, but I preordered it and have been playing since Nov 6 but I don’t know how to get my gamestop preorder camo thingy
They should be either codes on the receipt or on a card in the game case.
If you don’t see the codes on either, just contact Gamestop’s customer support and they will ask for some details on your receipt. When they verify what they need to they’ll email you the codes.