Как убить firefox из командной строки

Как убить firefox из командной строки?

Я пробовал:

pkill firefox # the command was known to work previously
pkill -9 firefox
kill -9 firefox # descibed in https://unix.stackexchange.com/questions/8916/when-should-i-not-kill-9-a-process
bash: kill: firefox: arguments must be process or job IDs
killall firefox #described in https://appuals.com/restart-firefox-command-line/

Все тщетно.

Вывод

ps aux | grep -i firefox | grep -v grep

v           2419  1.7  7.7 4026824 458876 ?      Sl   12:56   0:51 /usr/lib/firefox/firefox -new-window
v           2483  0.0  0.6 190540 38684 ?        Sl   12:56   0:00 /usr/lib/firefox/firefox -contentproc -parentBuildID 20210927210923 -prefsLen 1 -prefMapSize 246254 -appdir /usr/lib/firefox/browser 2419 true socket
v           2515  0.0  2.0 2407620 119704 ?      Sl   12:56   0:01 /usr/lib/firefox/firefox -contentproc -childID 1 -isForBrowser -prefsLen 102 -prefMapSize 246254 -jsInit 286204 -parentBuildID 20210927210923 -appdir /usr/lib/firefox/browser 2419 true tab
v           2553  0.5  2.6 2572708 156816 ?      Sl   12:56   0:16 /usr/lib/firefox/firefox -contentproc -childID 2 -isForBrowser -prefsLen 268 -prefMapSize 246254 -jsInit 286204 -parentBuildID 20210927210923 -appdir /usr/lib/firefox/browser 2419 true tab
v           2581  0.0  1.6 2406928 99740 ?       Sl   12:56   0:01 /usr/lib/firefox/firefox -contentproc -childID 3 -isForBrowser -prefsLen 4889 -prefMapSize 246254 -jsInit 286204 -parentBuildID 20210927210923 -appdir /usr/lib/firefox/browser 2419 true tab
v           2612  0.3  3.7 2648096 225204 ?      Sl   12:56   0:09 /usr/lib/firefox/firefox -contentproc -childID 4 -isForBrowser -prefsLen 5588 -prefMapSize 246254 -jsInit 286204 -parentBuildID 20210927210923 -appdir /usr/lib/firefox/browser 2419 true tab
v           2866  0.0  1.2 2373260 72628 ?       Sl   12:58   0:00 /usr/lib/firefox/firefox -contentproc -childID 5 -isForBrowser -prefsLen 5701 -prefMapSize 246254 -jsInit 286204 -parentBuildID 20210927210923 -appdir /usr/lib/firefox/browser 2419 true tab
v           2998  0.0  0.6 194220 39176 ?        Sl   13:12   0:00 /usr/lib/firefox/firefox -contentproc -parentBuildID 20210927210923 -prefsLen 5926 -prefMapSize 246254 -appdir /usr/lib/firefox/browser 2419 true rdd