Steps
- Reach Union Level 2 (a few minutes of Chapter 1). The menu is locked before that.
- Open the Terminal (Esc on PC; terminal icon on mobile).
- Settings (gear, usually bottom-right).
- Other Settings (wrench) → Account row → Redemption Code.
- Paste the code, confirm. Open the mailbox and claim. Unused mail is deleted after a couple of weeks.
Limits Kuro actually enforces
- One use per account, until the expiry on the official post.
- Global codes are for America / Europe / Asia / HMT / SEA together. China server is a separate list.
- Livestream codes die fast — often 24–48 hours. Do not sit on a screenshot from last month.
Lost the account that already redeemed a code? That is login, not codes — recovery.