Your Monitor comes with a 6V, 3.6W power adapter. If this power adapter is damaged or missing, do not attempt to find another one. Contact support.
The power adapter plugs into the Monitor on the side, as shown below.
Note: The barrel connector of the power adapter will not be fully inserted into the Monitor (expect a few millimeters of the silver end to be showing.) If the connector is fully in place, you should see the LEDs on the top of the Monitor light up.