I decided to drill the doors since I’m using those sensors reliable for 2 Years +
To insert the sensor you need to drill the door with a 21 mm Forstner Wood Drill Bit
To clean the insert you can use a Wood polishing drill head
To drill the hole for the magnet you need a 6 mm Wood Drill Bit
The antenna is located where the green thing from the bottom right corner of the apartment plan.
The doors/walls don’t seem to interfere with the signal in any way!
Antena is a CC2531 Texas Instruments
Software is Zigbee2MQTT