Source: https://old.reddit.com/r/ArmoredWarfare/comments/j4ovel/just_a_little_something/
Can confirm codes from both lists work. There are over 900 codes on each list, if you're unlucky enough to nab a used code just try another one.
Backup read-only copy of the two lists in case they go poof or vandalized, since the originals weren't protected:
https://drive.google.com/file/d/16ZV0PzjsLDwvv7VgXeHtBINZiRvXwEPP/view?usp=sharing
https://drive.google.com/file/d/1o0EY6ciKon2EjmK5TIKUAZ8kNDFAeH-q/view?usp=sharing
Edit: code can be redeemed at your profile page on the AW webpage (log in first): https://aw.my.games/en/user