Here sonoff 4chpror2 wifi smart switch is a worthy investment.
Sonoff switch garage door.
Just start flashesp8266 exe choose the bin fine and flash.
After setting up the wifi data the device will restart.
These are going to the reed switch and will tell you if the garage is open or closed.
Use a usb cable for power.
The door sensor reed switch is now power2.
No idea how to retrofit.
If you have eagle eyes you might note that my payload on is off.
Connect female end of jumper wires to gpio 14 and ground.
This rule toggles the fake relay on the tasmota gui and can be monitored via the power1 mqtt topic.
Sonoff wireless wifi smart home products turn your home into a smart home at low price.
Also note that again yours could be named sonoff and mine is named sonoffgarage.
The sonoff units take mains power at one end and delivers switched mains power at the other internally they have a small transformer to run the esp8266 device and a 10amp relay to switch the power.
The rest is the save as when flashing sonoff.
Now here is the garage door binary sensor for the reed switch.
Plug the microusb cable to the nodemcu and while pressing the flash button plug in the usb into your computer.
Remote control automate monitor home devices like lights temperature and more.
Powerretain 1 makes the state of the door being open or closed be retained during a home assistant reboot.