Failed to display fixed name

$items[] = array(
‘order_id’ => get_the_ID(),
‘wccs_status’ => $order->get_status(),
//’customer_name’ => $order->get_billing_first_name . ‘ ‘ . $order->get_billing_last_name,
‘customer_name’ => $first_name = method_exists( $order, ‘get_billing_first_name’ ) ? $order->get_billing_first_name() : $order->billing_first_name,
‘customer_source’ => $customer_source,
);