Here’s how to install window sensors, which are typically wireless and backed by adhesives:
Stick one piece of the sensor on the window frame and the other on the windowpane, about one inch apart.
Activate the sensors according to the manufacturer’s instructions.
Add them to your home’s Wi-Fi network.
Name them after the window they’re on (e.g., “front of the living room” or “bathroom”).
Test the sensors to be sure they work.