Integrating Plex Webhooks with KM, via KM Remote or Public Web triggers

I recently bought a subscription to Plex Pass in order to trigger some automations in Keyboard Maestro and other apps when certain media files are playing, paused, etc. Plex is supposed to send out a webhook request to a URL (local or external) that I can specify in their settings. I assumed I could trigger a KM Macro by using either its Remote or its Public Web Trigger in Plex's settings, since I've never had any problem doing the same with other services, but after trying both triggers, with and without parameters, I couldn't get it it work. Could the issue have something to do with the fact that PLEX is sending out a json payload with its request? If that's the case, and KM cannot read/turn the payload into a TriggerValue, shouldn't the request at least trigger the KM Macro with an empty parameter/TriggerValue?