GuzzleHttp cURL error 7 报错

代码如下

$client =new Client;
        $api='https://www.xxxx.com/api/Auth/PostToken';
        $response=$client->request('POST',$api,[
            'json'=>[
                    'UserName'=> 'clixxxt_cxxtials',
                    'ClientId'=>'client',
                    'Password'=>'xxxx'
                ],
             'headers' => [
                    'Content-type'=> 'application/json']

        ]);

        $response=$client ->post($api);

        dd($response);

总是报cURL error 7: Failed connect to www.xxxx.com:443; Connection timed out (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)，请教各位大佬，问题出在哪里？