It may seem obvious, but at gated locations, you must first open the entrance to drive in and out. Here is how you do it:
Entrance
When you are at the entrance of the reserved parking location, open the app,
Go to 'Parking sessions' and tap 'Start parking session',
Confirm that you are at the correct entrance and tap 'Yes, open entrance',
Drive in carefully once the gate or barrier is fully open,
If the entrance does not open, you can tap 'Try again',
Exit
When you are at the exit of the reserved parking location, open the app,
Go to 'Parking sessions' and tap 'Stop parking and exit',
Confirm that you are at the exit and tap 'Yes, open exit',
Drive out carefully once the gate or barrier is fully open,
End your parking session.