Twitch - Starting Your Xbox Broadcast Stream  

Once you are logged in to the Twitch app on your Xbox, you are able to start broadcasting. To start broadcasting, move to “Broadcast” on the top of the screen and press the “A” button.

Now you can select or update your Twitch settings and enter the “Title” of your stream.  To begin streaming, move down to the bottom and select “Start Streaming”.  Once you return to play your Xbox game, your stream will automatically begin.

Good Luck!