Dell P2723DE 27" 1440p USB Type-C Hub Monitor - Manual (Page 71)

Operating the monitor │ 71
Menu and Power button lock
Prevents users to access or change OSD menu settings on the display.
By default, the Menu and Power button lock setting is disabled.
To access the lock menu, press and hold the Up or Down or Left or Right direction
for four seconds. A lock menu appears at the bottom right corner of the display.
NOTE: The lock menu can be accessed using this method when the
Menu and Power buttons are in unlocked state.
Select option:
To access the unlock menu, press and hold the Up or Down or Left or Right
direction for four seconds. An unlock menu appears at the bottom right corner of
the display.
NOTE: The unlock menu can be accessed when the Menu and Power
buttons are in locked state .