The LinkedIn login button should automatically show. However, it looks like one final checkin in JFBConnect never occurred.
The best/easiest way to get it to appear is to fix our mistake. To do so, please edit /components/com_jfbconnect/libraries/provider/facebook.php Around line 143, you'll see:
//if (SCSocialUtilities::isJLinkedInstalled())
//$html .= '<div class="jLinkedLoginImage pull-left"><a class="show" id="sc_lilogin" href="javascript:void(0)" onclick="jlinked.login.login();"><img src="' . JURI::root() . 'media/sourcecoast/images/provider/button_linkedin.png" /></a></div>';
Uncomment those lines by removing the two // at the beginning of each. That will make the button show automatically like we meant to.
Sorry about that, and please let us know if that helps or you run into anything else.
Thanks,
Alex