Parking lots with a barrier - when approaching the barrier, stop at the STOP line until the cameras scan the car's number and the barriers open. When you finish parking, pay for parking at the parking meter or in the app and then leave the parking lot.
Open parking lots - when entering an open parking lot, parking must be started with an app, SMS message or parking meter (if there is one). When you finish parking, make sure you stop parking and pay for it in the ways listed above.