How to access isispConfig3 websites created without domain names

[kmchen]

Hi,
I'm a total newbie with ispConfig that I got installed on an ovh dedicated server.
I bought the doc.pdf where it is said that I should be able to access freshly created websites but at whitch url ?
When I try http://ip_or_name_server/testsite.com/web/ I get 403 error with "client denied by server configuration: /var/www/testsite.com/web/index.html" in apache logs

I need that feature to test websites before real domain name transfers.

Thanks for your help