BigCommerce API连接到商店时出现问题

I'm trying to teach myself the BigCommerce API, but I'm having trouble connecting to my store.

I'm working on a local server(XAMPP). I granted this user api access. I copied over this page: https://raw.github.com/bigcommerce/bigcommerce-api-php/master/bigcommerce.php

and then set up my index.php

<?php

require 'bigcommerce.php';

use Bigcommerce\Api\Client as Bigcommerce;

Bigcommerce::configure(array(
    'store_url' => 'http://mydomain.mybigcommerce.com/',
    'username'  => 'coder1',
    'api_key'   => '123456678900098876665'
));

$ping = Bigcommerce::getTime();

if ($ping) echo $ping->format('H:i:s');