Read here for more information:
https://newsroom.sprint
You just have a be a Sprint customer. I’m assuming that each line can get a free large pizza.
Instructions:
Download the app.
Google Play: https://play.google.com/store/app…rint&hl=e
Apple App Store: https://itunes.apple.co
Make an account. When you reach the home screen, the free large pizza offer should be on there.