First, check the handle position to ensure the faucet is in the open position:
Next, activate the sensor by waving your hand under the arch of the spout, near the sensor area:
Then, confirm water supply to verify that the supply stops (valves) under the sink are fully open
If you have the Crue, Graze, Artifacts, Tone, Riff, Bellera, Simplice models, clean the sensor by gently using a soft cloth or sponge and rubbing alcohol to remove any debris.