PHP client script to push firebase notifications using cURL.

firebase_push_notification.php

<?php
//client script

$FCM_KEY = "__YOUR_FIREBASE_AUTH_KEY__";
function fcm_push($token, $title, $text, $uri, $img='', $custom_data=[]){
    global $FCM_KEY;

    $url = 'https://fcm.googleapis.com/fcm/send';

    $headers = array('Content-Type: application/json', 'Authorization: key='.$FCM_KEY);
    
    $body = array(
        'notification' => array(
            'title' => $title,
            'text' => $text,
            'click_action' => 'Open_URI'
        ),
        'data' => array(
            'title' => $title,
            'uri' => $uri,
            'image' => $img
        ),
        'to' => $token
    );
    $data = json_encode($body);

    $ch = curl_init ();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $data);

    $result = curl_exec($ch);

    return $result;

    curl_close($ch);
}
?>