Error updating Julia to 1.10.3 with UpdateJulia on mac?

Sorry i’m having a little trouble accomplishing this. Not all versions of Julia that I have installed appear in the applications folder so I can’t just delete all of them. When I try which julia in the terminal as per this post terminal returns julia not found even though I am currently running 1.10.2 and have installed every version since 1.7.

Also just wondering …will uninstalling previous versions also delete all existing project environments?