How do I save the position for emptying the gray water tank?

A) Permanently installed control panel

1. Switch on system
2. Symbol Tank emptying ≥ 5 Sec. Drücken
3. Bring the vehicle into the desired inclined position
4. Symbol Tank emptying again ≥ 5 sec. drücken
5. Storage is complete when another beep sounds and the LED turns off
6. Switch off system

B) Removable control panel

1. Switch on system
2. Long press the stop button (expert mode)
3. Briefly press the gray water tank button
4. Drive vehicle into position
5. Press the gray water tank button again (save)