How to start service in main activity by coding proximity sensor in service class - android-studio

Question

How to start service in main activity by coding proximity sensor in the service class.
my code not working please tell me
This Service class
public class ModeOnOff extends Service {
private SensorManager sensorManager;
private Sensor proximitySensor;
private SensorEventListener proximitySensorListener;
#Override
public void onCreate() {
SensorManager sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
if (sensorManager!=null){
Sensor proximitySensor = sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
if (proximitySensor!=null) {
sensorManager.registerListener(proximitySensorListener, proximitySensor, SensorManager.SENSOR_DELAY_NORMAL);
}
} else {
Toast.makeText(this, "Senor service not detected.", Toast.LENGTH_SHORT).show();
}
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Sensor();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
//Function
private void Sensor(){
proximitySensorListener = new SensorEventListener() {
#Override
public void onSensorChanged(SensorEvent sensorEvent) {
if (sensorEvent.sensor.getType()==Sensor.TYPE_PROXIMITY){
if (sensorEvent.values[0] > 3){
Toast.makeText(ModeOnOff.this, "Hii", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(ModeOnOff.this, "By", Toast.LENGTH_SHORT).show();
}
}
}
#Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
};
}
}
And This Main Activity
public class MainActivity extends AppCompatActivity {
Button btnSensor;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnSensor = findViewById(R.id.btnSensor);
btnSensor.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startService(new Intent(MainActivity.this, ModeOnOff.class));
}
});
}
}
I want to code the proximity sensor in the service class and start the service from the main activity
how to startService - startService(new Intent(MainActivity.this, ModeOnOff.class));