On the date of your reservation, enter the parking lot as usual, and follow the operator's instructions about where to leave your car. Then give your Parclick voucher to the operator.
Our staff there will check your reservation using the reservation code, and will give you a card that will allow you out, leaving a €15 deposit with the car park staff. The deposit will be refunded upon your departure when you return the card.
via dei Sulpici, 41