Facebook app creation app domain error

I'm trying to create Facebook app. Yet I had trouble right after creation wizard done his work.

Changing nothing in what wizard created I've got an error:

Error
You have specified an App Domain but have not specified a valid integration URL.
secure-citadel-xxxx.herokuapp.com must be derived from one of: Site URL, Mobile
Site URL, Canvas URL, Secure Canvas URL, Page Tab URL or Secure Page Tab URL.

I googled it and found no answer at what it might be..

Adding http:// and so on doesn't make anything more than another error of domain being invalid.

Does anyone know ho to deal with it?

Facebook changed their user interface for developer apps, so this can be tricky to find. For future people visiting:

1. Click Apps and then select your app.
2. Click the Settings button on the left side of the screen.
3. In the Basic settings, click the Add Platform button below the settings configuration.
4. Select Website in the platform dialog.
5. Enter your URL (localhost works here).
6. In the App Domains text input, add your domain that matches the one in the URL.
7. Save your settings.

The only allowed values in the App Domains field are URLs you already entered in at least one of you Select how your app integrates with Facebook block:

• Website with Facebook Login - URL
• App on Facebook - Canvas
• etc for the others