Create app on facebook

1. Go to Developers section of Facebook.

2. Click on "Apps" and Click on "Create a new app" (If you are not logged in then click on "Login" and logged self in).

3. A Create New App popup will appear then Enter "Display Name" and "Choose a Category" and click on "Create App" Button. Fill capcha correct and click "continue".

4. Your App interface will appear then Click on "Settings" tab and click on "+ Add Platform".

5. A popup will appear click on "Website".

6. Enter "App Domains", "Site URL", "Contact Email" and click on "Save Changes" Button.
Note :-
App Domains = example.com (only your site domin without http:// or www)
Site URL = http://example.com/ (must be http://yoursitedomain/)

7. Click on Settings>Advanced tab and check "Age Restriction" must be Anyone(13+).

8. Click on "Status & Review" tab click on "yes" a popup will appear to ask make app live then click on "confirm" button.

9. Click on "Dashboard" and get your App ID and App Secret(with click show button) copy and paste it where you want.