Does your Firefox web browser have a large cache of temporary files? Do you have an embarrassing web browsing history? Has it been a while since you last cleared your Firefox cache? If you answered yes to any of the above questions, you've come to the right guide.
Firefox becomes increasing embarsing when I try to backup to the cloud or do a timeshift. There should be a single button in Linux to clear all cache, including any snap deposits in /var/cache for security reasons I’m just saying. 
I would not be here trying to delete (not clear) my temporary files in Firefox using the standard preferences in Firefox security clear history/clear data. They are blocking that now somehow everyone
is complaining about. Your command line instructions don’t show which command to use for Ubuntu?
should I just go down the list you’ve shown here? or is there a certain one I should use? I’m assuming that whatever command prompt you send me won’t work because I never had “ANY” success copying any command prompt I’ve copied off the disinformation I try to understand on all this Linux instruction forum sites. please send me the terminal command in complete form not abbrev. I truly think that Firefox has out lived it’s favored partnership Ubuntu since it’s caved into google and downloaded that drive crap
on my system. I am so pissed off at all this BS you have to go though to escape all these suck monsters.