Phone OTP With -1

Lets Start By Creating Android Studio Project :

>> Create an Android Studio Project 

>> Lets Add Required Libraries for this project. 

1. build.gradle

buildscript {
	repositories {
	google()
	jcenter()
	}
	dependencies {
	classpath 'com.android.tools.build:gradle:3.5.3'
	classpath 'com.google.gms:google-services:4.3.3'
	classpath 'com.github.dcendents:android-maven-gradle-plugin:2.1'
	// NOTE: Do not place your application dependencies here; they belong
	// in the individual module build.gradle files
	}
	}
	allprojects {
	repositories {
	google()
	jcenter()
	maven { url "https://jitpack.io" }
	}
	}
	task clean(type: Delete) {
	delete rootProject.buildDir
	}