Playing other audio with mopidy at the same time

I don’t know too much about GStreamer but I see from https://docs.mopidy.com/en/latest/audio/ it uses “autoaudiosink” which, I think, in my case is pulse.

I need to be able to play other sounds (via gstreamer) while Mopidy is also streaming audio. But it looks like Mopidy gets an exclusive lock on the audio output.

For example, when I run

gst-launch-1.0 audiotestsrc ! audioresample ! autoaudiosink

While Mopidy is running it fails with “Connection Refused” from pulse. But when I run it when the Mopidy service is stopped, is generates and plays a tone no problem.

How can I configure all this to let me use gstreamer to play other audio at the same time?

I want to have Mopidy streaming music but then at the same time also be able to do something like:

gst-launch-1.0 filesrc location=whatever.wav ! wavparse ! audioconvert ! autoaudiosink

Thanks.