How to configure a redirect to www and vice-versa for a website on Plesk?
Note: This option may not work for WordPress based websites and any other websites that have a predefined configuration to use www or non-www in their code. Configure such websites through their administration panel or in configs. Make sure that there are no custom rules in Domains > example.com > Apache & Nginx Settings or in .htaccess files on Linux or web.config on Windows.
Go to Domains > example.com > Hosting Settings.
Set Preferred domain parameter to