Basic Usage

<?php
require_once('path/to/init.php');
$data = $ipsp->call('checkout',array(
  'order_id'    => 'orderid-111222333',
  'order_desc'  => 'Simple checkout page',
  'currency'    => $ipsp::USD ,
  'amount'      => 2000, // 20 USD
  'response_url'=> sprintf('http://shop.example.com/checkout/result')
))->getResponse();
// redirect to checkout page
$data->redirectToCheckout();