Need help regarding connecting mini MQ7 CO/Gas Sensor


I recently purchased this :

I do not know how to connect this to my adruino however. It has 4 pins. VDD, GND, D0 and A0. I have connected VDD to +5, GND to ground and A0 to a pin on my arduino and configured it as analog input.

I am using arduino nano but I have no idea how to write a code of this sensor. If anyone has used this before, please guide me.