PHP FIREBASE PUSH NOTIFICATION

pushnotification.php

<?php
function sendPushNotification($to = '', $data = array()){
    $apiKey = '';
    $fields = ['to' => $to, 'notification' => $data];
    $headers = ['Authorization: key='.$apiKey, 'Content-Type: application/json'];
    $url = 'https://fcm.googleapis.com/fcm.send';
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    curl_setopt($ch, CURLOPT_PROXY_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
    $result = curl_exec($ch);
    curl_close();
    return json_decode($result, true);

}
?>