See [[How to run Firefox when your profile is missing or inaccessible]] under '''Profile was deleted'''.

P.S. on macOS there is a Library folder and a '''Users''' "~/Library" folder which contains the Firefox folder. Your screenshot is of the wrong folder. See [[Profiles - Where Firefox stores your bookmarks, passwords and other user data]] under this section: '''Finding your profile without opening Firefox''': 1. Click the Finder icon in the dock. On the menu bar, click the Go menu, hold down the option or alt key and select Library. A window will open containing your Library folder. 2. Open the Application Support folder, then open the Firefox folder, and then the Profiles folder. 3. Your profile folder is within this folder. If you only have one profile, its folder would have "default" in the name. From https://support.mozilla.org/en-US/questions/1446129#answer-1650375 <blockquote> 4/30/24, 1:08 PM Primary location used for the main profile that keeps your personal data (Root Directory on about:profiles). * ~/Library/Application Support/Firefox/Profiles/<profile> In Mac OS X v10.7 and later, the "~/Library" folder in the Home directory is a hidden folder. </blockquote> See also https://kb.mozillazine.org/Show_hidden_files_and_folders#Mac_OS_X