This function in DTM returned the URI of the page where run. If it were run on https://www.example.com/Things/Stuff?foo=cats&bar=dogs#supersale , it would rteurn "/Things/Stuff?foo=cats&bar=dogs".
It does not exist in Launch.
Create a data element (call it URI if you wish) using Core > Custom Code. In the custom code section enter the following:
return (document.location.pathname + document.location.search);
You may then replace