The Main Flipcause Integration Code is what allows the floating and pop-up functionality to work for Flipcause buttons. It needs to be installed into the Header or Footer area of the website, which allows it to be available on every single page. If installed in this way, it only has to be installed once per website! The code by itself does not create any visible elements on your site, it works in the background to allow the popup and floating functionality to work for all the Flipcause buttons throughout your website.
You will see this code whenever you use the Code Generator in the Integration Center and choose either a floating button or a button that creates a popup, it will be the first code listed.
To install the Main Integration Code on your WordPress site, you'll need to install and activate the Embed Code plugin for your website (https://wordpress.org/plugins/embed-code/).