Hello, friend!
Use either of the following methods to reset Huawei ONT to default:
1. Choose System Tools > Restore Default Configuration from the main menu on the web page and click Default.

2.Hold down the RESET button for at least 10 seconds to restart the ONT with factory settings.
Note:
Do not reset Huawei ONTs randomly. Otherwise, the ONTs may fail to access the Internet. If an ONT cannot access the Internet after a reset, contact your ISP.
Thanks!