NIKKE codes

1. 1
   Open NIKKE and get past the lobby loading screen.
2. 2
   Tap the menu in the top right corner and open Redeem Code (it's also linked from the Notice page as the redemption portal).
3. 3
   Paste the code and confirm.
4. 4
   Rewards arrive in your in-game mailbox. Claim them from there.

Each code works once per account. Some codes also have a server-wide redemption cap, so a valid code can say "used up" if your server hit the limit.