Can't connect with Facebook

Hi.

I've created a Facebook app to use with this plugin. Already have the app ID, secret key and API key, but when going to next step, grant permissions, the new window that opens is showing this error message:

API Error Code: 191
API Error Description: The specified URL is not owned by the application
Error Message: redirect_uri is not owned by the application.

Don't know what to fix or what to change. Please advice.

Thank you.