Hello, friend!
For the question you described, you can try the following login number and password:
User name: root
Password: adminHW
The account and password vary depending on the region. You can also refer to the nameplate on the device.
If you need a device administrator account and password, you can only obtain the account and password from the ISP. If you cannot obtain the account and password from the local ISP, you can call the ISP national hotline. If you still cannot obtain the account and password, you can complain about the ISP service.
To change your Wi-Fi password, click: How to Get Your Wifi Password
Thanks!