Android Push notification using php

Android push notification using php script. This code will act as web service for the android developers make the app to send push notifications. Before using this code, You have to create a project in google console and get the API key for authentication. Also you have send the Device Token of each mobile.
You can also get device token in with your mobile client side function. So, we you trying to execute the push notification through web service. Should be pass two parameters API Key and Device Token.