Here are the instructions from the manual of the Direction Desk for the keypad.

Keypad use

1. Initialization Procedure

Step	Operation	Motion
1	Press and hold ▲ and ▼ simultaneously for more than 3 seconds	Legs begin to move down at half speed of normal operation
2	Keep pressing ▲ and ▼	Legs move down to the lowest positions and rebound 2-5mm, then stop
3	Release ▲ and ▼ together	Initialization is completed