I installed the plugin but I can't get it to work, or

Hi,

I installed the plugin but I can't get it to work, or I don't understand what it's supposed to do.

I installed it on a test site. I created two users, admin and a subcriber. The chatbox is added to a page with shortcode.
The box shows up, but I can't see another user to chat with.
Active users is on and both users are logged in.

Do I miss something?