Required gstreamer plugin 'nice' not found
I'm trying to run the webrtc-send-recv example here: https://gitlab.freedesktop.org/gstreamer/gst-examples/-/blob/master/webrtc/sendrecv/gst/webrtc-sendrecv.c
I've followed the instructions and have successfully built the executable, but when running it I get a "Required gstreamer plugin 'nice' not found" error.
I've manually built gstreamer v1.19.1, base plugins and the good the bad and the ugly plugins as well as manually built and installed libnice as instructed here https://github.com/libnice/libnice but still get this plug-in error.
I'm using Ubuntu 18.04.3 LTS for this.