Easy module to install.
After installation you can chat directly. This does not really look professional.
In the settings you can change this..
Via Manage- Configuration - Web services - Configure Drupalchat
Choose for iFlyChat Server in Choose Polling Method.
You can pick up the APP id and API Key on the website iFlyChat.com (first register)
You can get for each site where drupalchat is running a APP id and API Key on the same account. Generate a key for your domain.
Copy the APP ID and API Key and paste it into your settings.
There are no more settings are required.
From now on, drupalchat works.