While in game:
Press start
Social
Shift
If you’re logged into a shift account you’ll be able to enter a shift code.
This is the Code that I used to get one gold key:
ZFKJ3-TT6FF-KTFKT-T3JJT-JWX36
Once entered, hit ‘submit’
Press RB to go to ‘Mail’ and you should have your gold key ready to redeem.
The gold chest itself that you need to open can only be found once you’ve reached Sanctuary which is your main base of operations that’s unlocked shorty after progressing through story missions.
The gold chest will become marked on the map once you’ve gone around sanctuary for the first time. It will most likely appear after talking to Tannis or marcus. (They will be marked on the map for the mission)
If you’ve redeemed your key like above you’ll be able to walk right up to the chest and open it shorty followed with a lovely sound of an achievement popping
If you don’t have a shift account you’ll need to go to
https://shift.gearboxsoftware.com and create one there, then link it with your Xbox account.