Question: How to set up redirect from a domain with www to a domain without www, how to glue pages?

Answer: When adding a new domain in ISPmanager control panel, it is automatically assigned alias with www. Therefore, redirect from domain with www to domain without www ususally occurs automatically.

If it doesn’t happen, then you have to indicate the following lines in .htaccess file (which is in your domain directory) in order to glue pages with www and without www.   

 RewriteEngine On 
 RewriteCond %{HTTP_HOST} ^$ [NC] 
 RewriteRule ^(.*)$$1 [R=301,L]

  where – Your domain name with the zone.

You can check domains gluing by just typing domain with www in browser address bar. If a site opens without www, then redirect works properly.