The autoconfiguration from the FOP2 Manager has some triggers to run a php script to get new configuration. The script is by default located in /var/www/html/fop2/admin/update_conf.php . If that script is run, new extensions should be picked up and displayed on the FOP2 Manager. Also, when you add a new extension into your web backend (Freepbx, Thirdlane, etc), then the same update_conf.php script is going to be executed when you load the dashboard in the FOP2 Manager itself. That load is INSTANT, there is no cron job or anything. But you either have to reload asterisk/fop2 and or log into the fop2 manager to pickup the changes.

Best regards,