Creating facebook app with callback url

I am creating a facebook app. And I want to let users to login to my website using it(Using passportjs).

But to do that, I need to give callback url(my website url). But I couldn't find that field in the facebook app creating page.

Am I missing something? I have searched for it for a quite long time.

Writing as of Feb 2, 2014 I found these instructions to be current;

  1. Go to your app
  2. On the left-hand sidebar, click Settings
  3. Under the main section, click Add Platform
  4. Click 'Website'
  5. Specify your callback in the Site URL field (e.g. http://localhost:3000/auth/facebook/callback).

The setting is on the Basic page for the app.

  1. Go to https://developers.facebook.com/apps
  2. Click on your app on the left side
  3. Click Edit App button in the top right
  4. Under the "Select how your app integrates with Facebook" section click "Website with Facebook Login"
  5. Specify your callback in the Site URL field (e.g. http://localhost:3000/auth/facebook/callback).