Having this snippet installed on your site allows you to track the activity of known visitors to your website (leads, contacts). Then based on their activity on your site you can trigger certain actions like pop up messages, or trigger email sequence. Additionally, when viewing lead/contact data within Flexie you will be able to see their historic activity on your site.
The first step required is to log in to Flexie and click on Settings.
From the pop out menu, select configuration.
Then from the configuration settings, copy the provided tracking code.
The best place to paste this code is usually in the header of your site. Depending on the nature of your website this can be done in a variety of ways. I tend to use WordPress for most of my sites, and use Google Tag Manager to manager all my site scripts. Using GTM allows asynchronous (fast!) loading of all these scripts and minimises loading delays.