That middle screen almost looks like the Twitch page that informs you as to which permissions the application wants. Twitch handles that itself. Then, from there, Twitch pushes the user to your redirect_uri which you give Twitch with your application and Twitch will automatically reroute to when you provide that in the authorize endpoint:
https://api.twitch.tv/kraken/oauth2/authorize?response_type=token&client_id=MY_CLIENT_IDf&redirect_uri=http://MYHOST/twitchapi.html
Did you register an Application with Twitch to get your Client ID and Secret ID and register your redirect_uri?