define( 'API_ACCESS_KEY', 'YOUR-SERVER-API-ACCESS-KEY-GOES-HERE' );
$registrationIds = $_GET['id'];
$msg = array
(
'body' => 'Body Of Notification',
'title' => 'Title Of Notification',
'icon' => 'myicon',
'sound' => 'mySound'
);
$fields = array
(
'to' => $registrationIds,
'notification' => $msg
);
$headers = array
(
'Authorization: key=' . API_ACCESS_KEY,
'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;