Select Websites on the left sidebar.
Find the chat box you'd like to install and click on Get Code Snippet in the bottom right.
The first option gives you the snippet that you can add to your website code. You also have the option to use our Wordpress and shopify plugins under the More Setup Options link.
If you're not sure where this snippet goes in your website code, click on the More Setup Options link to expand the options including email the snippet to your webmaster.