How to redirect a domain with www prefix to a domain without www?
If you want to redirect, for example, the address https://www.domain.pl to https://domain.pl
create a .htaccess file in the main folder with the content:
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]
RewriteCond %{HTTPS} on
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]
Remember that in the "domains" tab you must have two addresses connected, with
www.and without, so for our examplewww.domain.planddomain.pl