You'll have to enter the code "FREETHROW" when ordering to get your freebie, which will come in the form of 25 Papa Rewards bonus points that can be used through April 17, 2016 (when they expire). If you're not a member, you'll need to sign up for the free program to get your free pizza.
25 points is just enough for redeem for a large, 3-topping pizza but they can also be used for various side items such as Garlic Knots, Cheesesticks, and a large Chocolate Chip Cookie (which all cost 10 points each).
The free pizza/points deal is available for a limited time through April 4, 2016.
Photo via Papa John's.