Enabling Facebook SSO requires that you have a Facebook account of your own. You will also need to restart your NodeBB instance a couple of times during the process. This will shut down your forum to users for a short period each time, so if you run a busy forum you may wish to do this during off-peak hours.
Install and activate plugin
Enable Facebook sign-on
Returning to NodeBB, copy and paste the Application ID and Secret code into the appropriate places on the Facebook menu page. You can also allow users who sign on with Facebook to skip the standard email verification step since Facebook usually does a good job of verifying these emails, but this is up to you. Be sure to save these settings. Once you are done, you will need to restart the forum one more time.
Once your forum restarts, new users will be able to join your forum using their Facebook ID. This option will be added to the user registration page automatically.