Thanks for using the plugin. Did you follow the steps for setting up an app and getting the app id on Facebook?
– Go to https://developers.facebook.com/.
– Log in using your existing Facebook account or create a new one.
– Under “My Apps” in the header, select “Add a New App”.
– Select “website”.
– Choose a name for your new app.
– Skip the quick set-up and go to your app\s dashboard. The App ID will be at the top under your app\s name.
– Under “Settings”, fill in the fields for “Namespace”, “Contact Email”, and “Site URL”. Facebook sharing will not work unless the Site URL matches the url of your WordPress site.
– Finally, go to “Status & Review” and click the button to make your app public.