First go to https://developers.facebook.com/ APPS – Create new APP
After you created the APP, go to SETTINGS.
Make sure to fill the APP domain field with the domain you installed the plugin on. It’s mandatory.
Click on Add Platform and select the PAGE TAB.
Now, fill out with the link from the Facebook Integration module .
Now, in the Facebook Integration module, fill out the key & secret, SAVE THE SETTINGS, and after that, click on ADD PAGE TAB button.