If you would like to add in Google Tag Manager, Analytics, Tracking or JS, please follow this guide:
Login to your website
Search for "Tracking"
In the Tracking are, copy & paste the necessary code so that it appears in your header.
If you need some extra code in the body of the page, e.g. Google Tag Manager requires code immediately after the opening body tag, then do the following:
Search for "Stacks"
Choose the stack you need, e.g. "Tracking, immediately after opening body tag"
Add Block > Choose "HTML"
Copy & paste code into block & save
Click on faint dotted line, from pop up menu select "Choose Custom Template"
Approve Changes button - click this
Check that the code is on your website as expected
Beginners Guide to Google Tag Manager: https://blog.hubspot.com/marketing/google-tag-manager-guide
Google Analytics with Google Tag Manager: https://support.google.com/tagmanager/answer/6107124?hl=en
Facebook Pixel with Google Tag Manger: https://www.megalytic.com/blog/how-to-install-and-debug-the-facebook-pixel-using-google-tag-manager