Automatic Registration with FB email login as Username?

Yes! In the Configuration -> User section of JFBConnect, there's an option for "Auto Username Prefix:". Change that to "email" or one of the options for a different automatic username.

Hope that helps,
Alex

Awesome! Glad to hear we could help. Should you need anything else, as always, just let us know.

Finally, if you haven't already, please consider leaving a rating and review for JFBConnect, or our support, on the Joomla Extension Directory. It certainly isn't required, but is very appreciated:
extensions.joomla.org/extensions/social-...ook-integration/7215

Thanks, and good luck,
Alex