How to change URL handler for firefox? Basically I want firefox to open URLs starting with "ssh://whoever@wherever" using iterm2.

Unfortunately I didn't pay attention - the first time I tried this, Mac Os suggested to use Terminal, and stupid me also clicked the checkbox to remember that setting. Now I can't figure how to undo/change that decision.

I have seen this question - but unfortunately that one is 7 years old and seems to be outdated (my preferences->profile window doesn't look at all like the one shown in the existing question).
To fix this, you need to delete/change the association within Firefox.


Go into Firefox Preferences (hamburger menu in upper right hand corner of window or press ⌘ Command,)
Scroll down to Applications.  You can either scroll through or search for the association you wish to modify


Delete the association; the next time you click on the link it will ask you what you want to do.  Or... change the association to the application you wish to be opened.