Chair sensor help

Hardware
1

Hello everyone!

I am very interested in making my presence detector for my office chair.
On the same simplified with a FSR sensor and a hack Aqara Contact Sensor, but wanting to favor a Thread communication rather than Zigbee, I got the Aqara P2 which has the advantage of being Matter compatible via Thread.
However, after opening the box I can’t identify the READ SENSOR because I don’t see any resistor, so I don’t know where to plug/solder my two wires.

I’m posting a photo of the motherboard if anyone can help me.

Front panel:

AVANT
AVANT1920×1440 413 KB

Many thanks in advance

2

In normal use, the magnet is positioned on the rear side of the card, perhaps on the back.

Rear panel:

ARRIERE
ARRIERE1920×1440 481 KB

Many thanks in advance

3

Nice idea!

4

image

This would have to be the reed that is pulled to make the contact to activate detection as it’s also marked on the casing where the detection point is being the center of the main unit.