1. According to the official instructions: click the "Settings" icon in the upper right corner of the interface - Redeem Code - Enter the Redemption Code
2. However, many players cannot find the location of the redemption code when they click Settings in the game. This is likely to be a bug in the game. Players need to wait for the official to fix this bug. The official should have received this feedback at present. I believe this bug will be fixed soon!