从服务器获取响应但未在设备上接收FCM推送通知

Question

以下是向https://fcm.googleapis.com/fcm/send发送请求后的回复：

{"multicast_id":5611071026900823002,"success":1,"failure":0,"canonical_ids":0,"results":[{"message_id":"0:1492463891506691%01d24181f9fd7ecd"}]}

但我无法在Android设备上收到任何通知。

这是我的PHP代码：

private function sendPushNotification($fields) {



        //firebase server url to send the curl request
        $url = 'https://fcm.googleapis.com/fcm/send';

        //building headers for the request
        $headers = array(
            'Authorization: key=********' ,
            'Content-Type: application/json'
        );

        //Initializing curl to open a connection
        $ch = curl_init();

        //Setting the curl url
        curl_setopt($ch, CURLOPT_URL, $url);

        //setting the method as post
        curl_setopt($ch, CURLOPT_POST, true);

        //adding headers 
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

        //disabling ssl support
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

        //adding the fields in json format 
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));

        //finally executing the curl request 
        $result = curl_exec($ch);
        if ($result === FALSE) {
            die('Curl failed: ' . curl_error($ch));
        }

        //Now close the connection
        curl_close($ch);

        //and return the result 
        return $result;
    }
}