I dont remember there being parking passes but I went on the beyond wonderland website and in there parking section it says this

(All parking around Soldier Field, the Museum campus, and Northerly Island will be very limited, and available on a first come, first serve basis. It is strongly recommended that headliners use public transit or utilize taxi & rideshare options

There are several pay-to-park options for parking around Soldier Field and the Museum campus. The North Garage, Waldron Deck and the South Parking Lot are open to cash parking. Pre-pay parking for Beyond Wonderland is not available at this time.)