send notification to android single device using fcm.

<?php

    define( 'AIzaSyCYpVYwK42m4k_WAE3Tc-EZwRLo9_A89vA', 'AAAA0r_x_cs:APA91bEMJ8IpI-n1rxE7VwRUbnAFzm9WULKFHfeYehnkhu2RtXc0Tl0YmupuL6mkp8p3mDytINr5fGzJCDKdePKAzmkn1A7bjHletWonepazDSDCU8K4UJFkq-NXbEUlzKB5lvH1AzxX' );
   // $registrationIds = $_GET['id'];


$registrationIds =  'evbtIS1d2cw:APA91bHo-Tqi7U6aqkFbsBHFBpi5ZOnmZobEDr2bh9E2KomK_LM7VhIoMm0xQhaPF9AhZ6N1bXD4_WI8AF0WywG417sT_PnFuZn5m8EmTG5ELpMwDQfkaUgNS-0SSQzXP8eR9puwW01c';

//$registrationIds = 'emUWiI8jZdw:APA91bEFMxsyYK62zghRl4UCzydU6LGxzyWQBr9wcrkaIRIkGMhp8gCEcaEzYNE22d8B29kv-saqBiTjkYBgDmsRml3QT-ZZM_55HdHv18TsvfdPmPQzKpVpaa1FDOgVf-9gKBUpgsXC';


     $msg = array
          (
'body' => '{"uid":"1235","message":"this is etst"}',
'title' => 'Title Of Notification',
              'icon' => 'myicon',/*Default Icon*/
              'sound' => 'mySound'/*Default sound*/
          );
$fields = array
(
'to' => $registrationIds,
'notification' => $msg
);


$headers = array
(
'Authorization: key=AAAA0r_x_cs:APA91bEMJ8IpI-n1rxE7VwRUbnAFzm9WULKFHfeYehnkhu2RtXc0Tl0YmupuL6mkp8p3mDytINr5fGzJCDKdePKAzmkn1A7bjHletWonepazDSDCU8K4UJFkq-NXbEUlzKB5lvH1AzxX',
'Content-Type: application/json'
);

$ch = curl_init();
curl_setopt( $ch,CURLOPT_URL, 'https://fcm.googleapis.com/fcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode( $fields ) );
$result = curl_exec($ch );
curl_close( $ch );

echo $result;