Open a PDF when Clicking on Polyline in Web Map

[MHO_Harbors]

In AGOL Experience Builder, I want to build an app. The app should function like this: when a user clicks on a polyline in the map widget, the option to open a PDF about that polyline also appears. So maybe I have  a polyline outlining a construction area and in My Content I have a georeferenced PDF that is the actual site plan for the the area. When the user clicks on the polyline, an option to open the PDF should appear. I cannot seem to get the trigger in the map widget to work like this however. I have also added an Embed Button in the upper right thinking I can somehow link the URL of the PDF to it, and to the polygon in the map. I cannot figure it out though.  Any advice? Thank you.

[apgis16]

I am trying to do this in Experience Builder but with only PDF attachments on a hosted feature layer. I know they released an Instant App that basically does this (with some browser limitations) but I want to do it in experience builder to be able to customize it more and add more widgets. Is there a workaound for viewing a PDF attachment in Experience Builder? I was hoping the Document Viewer widget would help but I see that's only for Autodesk stuff.