You specify your server’s host name during your very first login to Plesk. If you want to change the host name later, you can do it through Plesk.
Note: Specifying an invalid host name will result in unpredictable Plesk behavior and server malfunction. The host name must be resolvable from the Plesk-managed server, especially if Customer and Business Manager is installed.
To change your server’s host name:
Log in to Server Administration Panel.
Go to Tools & Settings > Server Settings.
Enter the new host name in the Full hostname field.
This should be a fully qualified host name, but without an ending dot (for example,