Node Red / Ring-mqtt dashboard

Does anyone have an example of a working ring-mqtt → node-red dashboard? Specifically, based around camera.[name]_snapshot?

When I run a state change node into msg.src and then into node-red-contrib-ui-media nothing renders in the dashboard. If I take the URL from msg.src and paste it into my browser, it renders the snapshot perfectly. (Example: https://homeassistant.example.com/api/camera_proxy/camera.backyard_snapshot?token=XYZ)

I found an example that uses a URL that resolves to a specific jpg file (https://github.githubassets.com/images/modules/logos_page/Octocat.png) and when I test with that URL it works.

Judging by the lack of response, the question is too vague. Include your flow and the debug output for it.