Hello, friend!
To change the password of the default ONT account, log in to the ONT web page first.
Click the System Tools tab and then choose Modify Login Password from the navigation tree. In the right pane, change the password of the root user.

Note:
1. After the user logs in to the ONT Web interface using the default common user name and password, the Modify Login Password interface is automatically displayed, prompting the user to change the initial password. After the user successfully changes the password, the Modify Login Password interface is no longer displayed in the following logins.
2. Change the initial user name and password after logging in to the web page.
Thanks!