You shouldn't need to add the permission request manually. Simply download the profile_plugins zip file to your computer, unzip it, and install the JomSocial profile integration plugin. Then, hit the profiles tab in JFBConnect and configure how you want the fields to be mapped to your JomSocial fields and whether or not to import the avatar.
For more specific information, see the Profiles section of the configuration guide:
www.sourcecoast.com/jfbconnect/docs/configuration-guide?start=8
Finally, since you're integrating with JomSocial, take at the common support questions for doing that integration. It may also help avoid some common issues:
www.sourcecoast.com/jfbconnect/docs/thir...ration-for-jomsocial
Hope that helps, and good luck,
Alex