That is a fairly large ask. What portion of the Service details that are displayed on that page would you have go to a popup instead (there are quite a few)?
It would be:
And if possible a button to open the metadata that's stored with the item like if you click here in agol:
Its just a query to see if its possible and how you would go about it
That would involve changing the detailsClicked function in the AddData/search/ItemCard.js to instead make an esriRequest to the REST service endpoint to get the json back and then use something like the jimu.js/dijit/message.js to present the info to the user in a message popup.