You can check the nameplate on the bottom of the device to get the management password or use the Wi-Fi password.
If the router is bound with the App, you can click Settings > Advanced > Management Password on the App to get the management password.
If the password is still incorrect, press the RESET button on the router for 10 seconds to restore the device to factory settings. The password will be restored to the default management password.
Note: After the device is restored to the factory settings, you need to configure the network and connect the device again.