How to create a Facebook Application
To use some of the Facebook extensions you need to create a Facebook Application and get an Application ID, Secret Key or API Key.
First of all you need to be logged into Facebook to create an Application. If you don't have a Facebook account you can create one for free at www.facebook.com.
When you are logged into Faceboo, go to Developer Section.
Click on the + Set Up New Application button (at the top right of the page)
If you never created an Application in your Facebok that you might see a Request for permission box, Click Allow on that.
Type your Application Name (example: Ahmed' blog) then select Agree and click on Create Application.
On the next screen you might be asked for a Security Check. Enter the text in the given box and click submit.
On the next screen you will see your application created as shown in screen shot below.
Click on Web Site tab and enter your website URL in Site URL field. Enter your site url with an ending slash (for example: http://mywebsite.com/) in Site URL and click on Save Changes
For Fanbox you will need to copy API Key and paste it in Fanbox settings page in yout website.
After changes are saved click on Back to My Applications.
Next you will see all your Facebook Application listed on left column. By clicking on the one you can see its Application ID, API Key and Application secret.
Application ID is needed if you are using Facebook Connect SDK plugin. You can find Facebook Connect settings by going to Extensions > Plugins Manager and then clicking on System – Facebook Connect SDK.