Technically speaking, you can place bluebot on just about anything since it clamps on.
However, it will not accurately measure flow from underneath your kitchen sink.
In order for the ultrasonic transducers to successfully measure flow, the pipe needs to be pressurized with water. Your main water line is pressurized, allowing bluebot to accurately measure water data.
The pipe underneath your sink is not pressurized, and has a significant amount of air present. Ultrasonic technology and air do not go well together.
If you would like to speak to a member of the bluebot team, simply navigate to Settings > Support from within the app and choose your preferred method of communication. Otherwise, you can email firstname.lastname@example.org