Here is new website form in SolidCP 1.3

{{apimage "newweb.png" ""}}

It allow to create new website on existing domain. Is the new form changed in a new version of SolidCP?

That is with "Enable Hostname Support: " enabled.

In my example (and yours) the hostname support isn't enabled on the host plan, which only allows the full domain.com and if it's in use --> it will not be displayed.

I've got it!

Thank you, Marco

Marco, please, check regex on creating 4 level domain name. The same error like ccTLD.