Screen shot

Hi! It is a pity that you did not create an account in firefox sync. Try to find the places file.sqlite. Once found, import the found file into firefox

Sync is an optional feature. Upon installation Firefox automatically creates a profile.

The library path shown in your screenshot isn't correct, the profile wouldn't be in a folder named "Extensions.

See if this support article helps you find your profile: https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#firefox:mac:fx65

Firefox uses two locations for the Firefox profile folder, so make sure to look in the correct location.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:preferences page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Location used for the main profile that keeps your personal data (Root Directory on about:profiles).

• ~/Library/Application Support/Firefox/Profiles/<profile>/

Location used for the disk cache and other temporary files (Local Directory on about:profiles).

• ~/Library/Caches/Firefox/Profiles/

See also:

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

If you use the Time Machine or other backup then try to restore file(s) from this backup.

• http://www.apple.com/support/timemachine/

Thank you all immensely for your help, this worked and I was able to find my most recent .jsonlz4 file by search in Finder!