Hi,
Copy the full script provided to you by the 3rd party.
Go to Dashboard > Settings > Custom Element
Create New and paste the code in it.
Based on the 3rd party documentation set it the Head, Body Start or Body End.
Apply it to the relevant pages
IMPORTANT: it will only work on live site under your own domain (not on website under the wixsite.com domain).
(P.S. please do not put questions in code block. it makes it less readable).