GNOME has blocked access to the dbus call for showing OSD, so as a workaround until an official method for triggering OSD is available this extension can bridge the gap.
It listens on DBus, and if its function is triggered it passes along the parameters to the OSD call.
Example making a dbus call from bash:
gdbus call --session --dest org.gnome.Shell --object-path /codes/merritt/OSDInterface --method codes.merritt.OSDInterface.showOSD 'audio-headphones' 'bash-label' 0.5 1Link to the GNOME function:
https://gitlab.gnome.org/GNOME/gnome-shell/-/blob/main/js/ui/osdWindow.js#L174