If it is not the main hosting domain and you do not need to have emails on this domain

Go to Administration to the domain you want to remove (Administration → My Domains → select domain). Click on the red button at the bottom Remove domain from hosting and park.

Select Redirect Domain in the left menu and set the address where you want to redirect the domain.

If this is the main hosting domain or you need to keep emails working on the domain

Upload a single file called .htaccess to the domain's FTP directory, which will contain the following:

RewriteEngine On
RewriteRule ^(.*)$ http://kampresmerovat.cz/ [R=301]

Of course, instead of the kampresmerovat.cz domain, fill in your domain where you want to redirect the traffic.