Nautilus integration for RPD?

When I upgraded to Fedora 30 this weekend, RPD was uninstalled. I installed it again according to the standard linux instruction (running the python script).

It works, but I know longer have integration with Nautilus - that is, when File Manager opens automatically in response to plugging in my card reader, I no longer have a button that says something like:
Contains photos - download iwth Rapid Photo Downloader.

I can’t remember where that came from (it’s been in my system for years). Any clues?

In theory line 7 in this file should be setting it up correctly:

But unfortunately it has not been working with Gnome for the last few Gnome releases. Frankly I have no idea why — perhaps there has been a change of policy in Gnome, or Gnome has a bug. If someone is able to find out what changed that would very useful.