I purchased the Meross Matter Smart Presence Sensor, MS600 US/CA Version directly from Meross Meross Matter Smart Presence Sensor, MS600 – Meross Official Store a couple of weeks ago. The delivered cost was about USD 30. It was easy to set up. I first set it up in the Meross app and used that app to generate the Matter code, which I entered in the openHAB Matter Controller Thing.
In the past I have tried various motion detectors, which were fine for movement, but if I sat at my desks, the motion sensor would soon stop reporting an alarm/presence. This device reacts quickly to motion/presence, stays on as long as someone is in the room, even if they are very still. Then quickly turns off presence when the last person leaves.