If you haven't done this already, make sure ShutterSnitch can receive from your camera by going through the setup guide via the collection overview -> Options -> Setup Guide. You'll only need to do this once.
Start the pairing process on your camera selecting "Send Images While Recording", "Smartphone" as the target device, and "Via Network" (for the "Direct" option, look at the post below).
When the camera asks you to open the smartphone app, open ShutterSnitch and enter or create a collection.
If the pairing is successfull, you should now be able to pick ShutterSnitch as a receiver on the camera. Take a photo and watch it arrive!