When braking the car on a slope, you should also engage first gear, and if there is an automatic transmission, engage the transmission lock. If the parking brake lever is fully tightened, it is impossible to move. If the lever is not fully tightened, then it is possible to move with the handbrake on.
When the handbrake is applied and the ignition is on, the brake system indicator light comes on.
To release the handbrake, pull the lever up, press the release button and lower the lever all the way down.
[The original article is available on the online resource AudiManual.ru]