If you are going to use Facebook plugins in Social Inviter module, you need Facebook App ID/API Key. If you already have any Facebook application you may use its Api Key, otherwise you need to create Facebook App.
How to create Facebook Application:
Go to https://developers.facebook.com (login, if necessary) and click on My Apps menu, then click on Add a New App submenu link.
On popup window choose WWW(Website) and type name of your new App and click on Create New Facebook Api ID button, then in new popup window choose Category and click on Create App ID.
type App Name
3. After creation you may put your site’s website url in the bottom of the page to the Site URL and Mobile Site URL textbox or click on Skip Quick Start button (at the top right) and on Settings panel put your domain name to the Site URL, Mobile Site URL and also you need to fill Contact Email field and then click on Save Changes button.
4. Go to Status $ Review app page and make it public.
5. Now you need to copy and past App ID from Facebook App’s Settings page and put it to Social Inviter's Facebook settings area.