Same issues, plain Firefox on macOS.
I finally got it working after trying a thousand combinations:
- In the Desktop app, in Settings, turn on ‘Allow browser integration’.
- Quit the Desktop app.
- In Firefox, disable the extension (right click the icon, Manage Extension, toggle it off)
- Quit Firefox.
- Open the Desktop app and log in.
- Open Firefox.
- Re-enable the extension.
- Open the extension, log in, and ‘pop out’ the extension into its own window.
- Settings, Account Security, Unlock with Biometrics. It should now ask for your fingerprint!
- DO NOT enable ‘Ask for biometrics on launch’. If you enable this, it looks like it worked but it breaks it (in my experience).
Doing this automatically created the ‘com.8bit.bitwarden.json’ file mentioned earlier in this thread.
IMPORTANT NOTE Biometrics ONLY works if the Desktop app is also running. If you quit the Desktop app, you’ll have to enter your password manually in Firefox.
Hopefully this works for others.