七牛上传文件服务器显示502，如何解决？

<?php
set_time_limit(0);

require_once  'vendor/autoload.php';

use Qiniu\Storage\UploadManager;
use Qiniu\Auth;

// 用于签名的公钥和私钥
 $accessKey = '***';
 $secretKey = '***';

 // 初始化签权对象
 $auth = new Auth($accessKey, $secretKey);

 $bucket = 'blog';

 // 生成上传Token
 $token = $auth->uploadToken($bucket);

 // 构建 UploadManager 对象
 $uploadMgr = new UploadManager();

$data = file_get_contents('11.jpg');
 $rt = $uploadMgr->put($token,substr(md5(time()),0,10).'.jpg',$data);

 print_r($rt);

<?php
set_time_limit(0);

require_once  'vendor/autoload.php';

use Qiniu\Storage\UploadManager;
use Qiniu\Auth;

// 用于签名的公钥和私钥
 $accessKey = '***';
 $secretKey = '***';

 // 初始化签权对象
 $auth = new Auth($accessKey, $secretKey);

 $bucket = 'blog';

 // 生成上传Token
 $token = $auth->uploadToken($bucket);

 // 构建 UploadManager 对象
 $uploadMgr = new UploadManager();

$data = file_get_contents('11.jpg');
 $rt = $uploadMgr->put($token,substr(md5(time()),0,10).'.jpg',$data);

 print_r($rt);