1. First Login To Facebook.
3. Add a new app.
4. Click setting dropdown menu and open "basic".
5. Paste your website url in the apps domains field
7. Click on "add platform" and select "website"
8. Give your website url in the given field and click on save changes Note: Make sure your app is live
9. Copy the app id and app secret and paste in the admin panel general settings section, in their respective fields. If after all this you still get an error, you will have to do the following additional steps:
10. Go back to https://developers.facebook.com/apps/ and choose your app.
11. Click the dropdown on facebook login and choose settings.
12. Make sure "Embedded Browser OAuth Login" is set to yes
13. Add the following in the Valid OAuth Redirect URIs text box: http://yourWebsite.com/fb-callback Note: if your domain name includes "https or www" include that in number 13.