Setup you facebook application
For the Facebook capabilities to work correctly you need to create a Facebook Application
To do so, follow these steps:
Click on “My Apps” -> “Create App”
Enter your App Display name (e.g WPAchievements) and Contact Email Adress and click on “Create App ID”
Click on “My Apps” -> Select you App” (e.g WPAchievements)” and click “Settings -> Basic”
Scroll to the bottom and click on “Add a plattform”
Select “Website” and enter your site URL: (e.g. https://wpachievements.net/ )
Scroll up to the Basic App Settings Overview.
Copy the values from the field: App ID and App Secret, and enter them in your wpachievements plugin settings: