My garage door like most has a low voltage pair of connectors that run to a button on the wall and when connected with a button press opens or closes the door this is what i needed to make the sonoff do.
Sosonoff wifi switch for garage door.
It is cool but expensive.
It is an absolutely affordable wifi garage door opener that can be triggered to open or close the garage door through your smartphone instead of leaving your car.
Here sonoff 4chpror2 wifi smart switch is a worthy investment.
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.