One site, where I cannot edit the DNS at the registrar, do not "redirect"
toto.com to www.toto.com

How can I set it via virtualmin ?

Thanks in advance.

at the registrar make sure you have the proper A records for it as it will be faster then a redirect or the likes

I cannot edit the DNS at the registrar …
So … :slight_smile: ?

you had to point the domain through A records I assumed, not NS records which are sometimes not available at certain registrars.
toto.com is registered at Network Solutions? They promise easy DNS management

you can try a directive in the apache conf in the <virtualhost> container like: ServerAlias www.toto.com and add the A record in your zone file. There are probably better ways to do it. Or ask your registrar to add the A record for you