Park in the lot and pay early bird parking or purchase a monthly pass at https://interstateparking.com/milwaukee/1190 to park in the lot.
Park on the street (but not in front of the restaurant) and pay for parking from 2pm-6pm via the MKE Park app (after 6pm parking is free) or park in the parking lot (rates will vary).
Purchase a monthly parking pass online at https://city.milwaukee.gov/Parking/ParkingPermits or visit one of the locations in the link to purchase the pass in person.
Once a month hand in your receipts and the company will cover half the cost of your parking.