Occupancy (motion) switch wiring question
According to the documentation for the switch you're using, a grounded (neutral) conductor is not required.  The wiring diagram for your device looks like this



If your device isn't working, it's possible that you've reversed the wires. Make sure the black wire from the switch is connected to the line wire, and the red wire is connected to the load wire.

If the switch still does not function, verify that the grounding conductor is solidly connected, and that the ground is good.

If the switch still does not function, the device may be defective and need to be replaced.