I want to add the script after the page load, that is after the body tag, how can I do that??
One option - manually add embed code (Put as first node inside your navbar symbol for example).
By code - if you want this for GOOGLE TAG MANAGER its not make sense to add this by
append (With JS) - because this code is for cases the users disabled scripts.
You can follow the steps here…Custom code in head and body tags | Webflow University