PHP实现FCM推送

/**
     * @param $receive //推送用户
     * @param $title //推送标题
     * @param $content //推送
     * @param $m_txt
     * @return bool|string
     */

    public function send($receive, $title, $content, $m_txt)
    {
        $url = 'https://fcm.googleapis.com/fcm/send';
        $api_key = config(fcm.apikey);
        //准备消息内容
        $data = [
            'title'    => $title,
            'body' => $content,
            'url'=> $m_txt
        ];

        $fields = array(
            //群发使用registration_ids[为数组]  单个用户使用to
            'to'             =>$receive ,
//            'registration_ids' => $receive,
            'data'             => $data,
            'time_to_live'     => 60,
        );
        $headers = array(
            'Authorization:key='.$api_key,
            'Content-Type:application/json'
        );
        $json = json_encode($fields);
        // Open connection
        $ch = curl_init();
        // Set the url, number of POST vars, POST data
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 5);    //请求超时时间这里设置为5s
        // Disabling SSL Certificate support temporarly
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
        // Execute post
        $result = curl_exec($ch);
        // Close connection
        curl_close($ch);
        return $result;
    }