Code:
xdotool search --name "lxqt-notificationd" windowkill
Probably can be easily adapted to notifications handled by any other notification daemon, requiring one to see what they're called with xprop or something:
Code:
notify-send "bogus" "$(ls /usr/bin)" & xprop
Then click on the notification. "lxqt-notificationd" is the "_NET_WM_NAME(UTF8_STRING)" but also a lot of other things, I'm not sure which one is...