RoundCube with ISPConfig3 help

[pinguinito]

I am trying to install ROudCube in my ispconfig3.0.1.1 the only Howto is (I think) with ispconfig2 and no experiences at all; so:
{ I want set up webmail.example.com}
step 1 in the how to :


Step 1 - Create a website:

In ISPConfig, create a website via “New site” in the main menu.
On the tab called “Basis” use webmail for the hostname and myhostingcompany.tld for the domain name.

ispconfig3 > New site doesn't has tab called “Basis”
How can i set up this simple step in ispconfig3???
Creating a subdomain for example.com ?

Thanks