Your visitors can open the chat window by clicking on any button on your website.
The only thing that you need to do is to add "openLiveSupportiChat" css class to your button.
For exmaple: <button class='openLiveSupportiChat'>Live Chat</button>
You can also use this nice feature in the navigation menu of your website.
For example: <a class='openLiveSupportiChat'><p>Live Chat</p></a>