Toggle mute on the default sink (using the special name @DEFAULT_SINK@)

Control a running PulseAudio sound server.
More information: <https://manned.org/pactl>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

pactl set-sink-mute {{@DEFAULT_SINK@}} toggle

click the source code to copy install pactl on any operating system with command-not-found.com