Hello, friend!
The account you use for login is the default user account, so you cannot change it.
You need to ask the device provider for the administrator account and password.
Click the Network Application tab and then choose the DNS Configuration from the navigation tree. In the right pane, configure the DNS template, DNS parameters, and you can also configure static DNS domain name resolution.
If the password is incorrect, the following situations occur:
1) The password has been changed,
2. Your device is a customized product.
In this case, you need to contact the device provider for device maintenance.
Thanks!