分条网关和编码器错误

我通过在libraries文件夹中添加Stripe的php库并从控制器中调用它，将Stripe与codeigniter集成在一起:

public function index()
{
    require_once(APPPATH.'libraries/stripe/init.php');
    'Stripe'Stripe::setApiKey("sk_test_3LrFVGsJkjh65g8kj34dszEM2");
    'Stripe'Charge::create(array(
     "amount"        => 30000, // amount in cents, again
     "currency"      => "usd",
     "customer"      => "cus_8lVKwCV52ShUc7",
     "description"   => "Monthly Fee",
     "metadata"      => array(
        "Period"            => "May - June 2016"
         )
      )
    );
}

我得到一个旋度错误

我不确定是否以正确的方式做集成，或者我是否需要在我的代码中添加其他东西。谢谢你！