note : you have to fill the Facebook API in backoffice > settings >APIs
First you have to add a Facebook page in your app by clicking from “Add pages” to add it in the carrousel of your pages.
Then just enter the ID of your Facebook Fan Page in the appropriate field, for example for our Facebook Page: https://www.facebook.com/appboxstudiocms, it will be “appboxstudiocms”:
Please note that only facebook Fan page can be used , personal Facebook pages won’t work.
Then press “ok” to import your Facebook Fan Page.
Here is the result: