"If a fan is unable to scan a QR code, parking ambassadors will be available onsite to assist or fans can visit a pay station at the ballpark.
Fans must purchase day of parking or activate their pre-paid parking session before entering the ballpark to avoid receiving a parking violation."
From the article, so sounds like if you are not up on the technology there will be people, presumably with ipads or the such, to help or kiosks where you can swipe a card and enter your plate. Sounds like you get a ticket if you don't pay. I wonder if that's a normal Milwaukee city(assuming thats what they are in) parking ticket or something less formal that's more of a bill sent to you. My guess would be the parking ticket.