In order to monitor and interact with multiple websites, you will have to consider each website as a department.

This means that if you have 3 websites you wish to monitor, you will need to purchase 2 additional departments.

When applying the Support Icon Source Code to each site, you would select the code for each respective department and not the "whole company".

This is found in the Generate HTML menu item of the account dashboard.

Login to your account dashboard here: http://www.onlinechatcenters.com/account