See:

• https://support.apple.com/guide/mac-help/use-your-keyboard-like-a-mouse-mchlp1399/mac

The accessibility.tabfocus pref may not exist by default, if you want to use this pref instead of the system settings, you need to create a new Number pref with name 'accessibility.tabfocus' and value '7' (tab through all the fields).

• about:config => accessibility.tabfocus => 7

You can open the about:config page via the location/address bar. On the warning page, you can click "Accept the Risk and Continue" to open about:config.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Thank you! The browser about:config setting fixed the issue.

I hope that this becomes a default FF setting on mac installs so that accessibility users can easily navigate websites using their keyboard. There has been a push for web developers to build websites that are ADA accessible/compliant, and if the browser does not natively support keyboard navigation, those users with accessibility issues may have a difficult time navigating those websites using FF.

Chrome has keyboard TAB navigation enabled by default.

Thanks again for your help. :)

Firefox follows the Mac System preferences setting.

• [13]:System Settings -> Keyboard -> "Keyboard navigation"
• [12]:System Preferences -> Keyboard -> Shortcuts -> "Use keyboard navigation to move focus between controls"

This might change in future Firefox versions.

• 1843669 - Consider changing the default macOS focus behaviour to include links and form controls

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)

It's exposed in the settings in version 117+ on Mac as "Use the tab key to move focus between form controls and links" (Bug 1628476).