Click Work on Shape in the West quadrant of the Compass.
You'll notice that you return to the design view.
If not visible, double-click anywhere inside the viewing zone to see your model.
Select the end face of the bottom half of the case.
Drag the perpendicular axis of the Robot towards the connector.
Notice that you need to turn the part to see the connector face.
Release the mouse when a coincidence relationship is detected with the rear face of the connector.
When finished, click the background.