at the moment GPL script for autoinstallation doesen’t work on CloudLinux OS.
There is a way to force installation.
CloudLinux is based on centOS.
Unfortunately, Virtualmin won’t work properly on CloudLinux.
There are some things it does differently than a standard CentOS installation, and those things prevent Virtualmin from working properly.
Not to mention a big chunk of the benefits of CloudLinux don’t work with Virtualmin. I tried to shoehorn Virtualmin into CL before.
Don’t waste your time!
If you want something similar security wise, check out Atomic Secured Linux, which Virtualmin is compatible with.