Use a paperclip to press and hold it for about while the router is on.
Security and Access Management of the Xiaomi Router Administrative Password xiaomi router management password
Once the lights flash and the router reboots, all settings (including passwords) return to factory defaults. You can then set it up from scratch as a "new" router. Use a paperclip to press and hold it
Many models use "admin" as both the username and password. xiaomi router management password
Enter your current management password when prompted. 3. Changing Your Management Password