The first thing you'll need to do is add the code to your website.
This code is already included in ClientExec's customer (public) section. You only need to add it if you want to offer support chat elsewhere in your website, but note it will only work in pages under the same domain, subdomain and protocol (http or https) as where ClientExec is installed.
For your staff members to be available to chat, they will need to enable the chat plugin (instructions located here) and then chat the switch on Available to Chat? to the check mark.
The chat window will appear on your website as a small bar, that expands into this.
If after closely following all the previous steps chat still isn't working for you, try the following workarounds: