Regarding the 3rd party tracking function within the restaurant admin panel this can be used by online marketing professionals & agencies to receive tracking data within the Google Analytics and/or Facebook Pixel platforms.
Within this section, the Google Tag Manager integration can be enabled, which allows the online ordering system to be connected to the Google Analytics and/or Facebook Pixel platforms.
Google Tag Manager is a free tool that makes it easy for marketers to add and update website tags — including conversion tracking, site analytics, re-marketing, and more—with just a few clicks, and without needing to edit the website code.
For a general overview on how Google Tag Manager works you may check the links below:
Therefore the Tag Manager acts as a middle-ware between the ordering system and the Analytics or Pixel platforms
For a detailed guide on how to install the Tag Manager with Facebook Pixel access this link.
For a detailed guide on how to install the Tag Manager with Google Analytics access this link.