https://www.dunkindonuts.com/en/mobile-app -open the Dunkin’ app, click offers, then scroll to the bottom and enter promo code: MUNCHKINS23 to get an offer for a Free¬† Premium Sips Drink at Dunkin’. Expires 9/28, but the code has a limited amount available for people to add to their account so make sure you enter it soon. It seems to only be valid on Small, medium, or Large frozen drinks or Signature Lattes.