If you are being prompted for a password and don't remember setting one, try these common defaults: Blank / No Password:
After a factory reset, the default WiFi name becomes “Xiaomi_XXXX” without a password (open network) for the first 3 minutes. Connect to that open network, then go to 192.168.31.1 and set a new password immediately. xiaomi mi wifi router 4c default password 2021
If you cannot log in, the only way to regain access is to perform a factory reset If you are being prompted for a password