В некоторых задачах требуется получить объект заказа.
Вот некоторая шпаргалка.

// Get Order ID and Key
 $order->get_id();
 $order->get_order_key();
 // Get Order Totals $0.00
 $order->get_formatted_order_total();
 $order->get_cart_tax();
 $order->get_currency();
 $order->get_discount_tax();
 $order->get_discount_to_display();
 $order->get_discount_total();
 $order->get_fees();
 $order->get_formatted_line_subtotal();
 $order->get_shipping_tax();
 $order->get_shipping_total();
 $order->get_subtotal();
 $order->get_subtotal_to_display();
 $order->get_tax_location();
 $order->get_tax_totals();
 $order->get_taxes();
 $order->get_total();
 $order->get_total_discount();
 $order->get_total_tax();
 $order->get_total_refunded();
 $order->get_total_tax_refunded();
 $order->get_total_shipping_refunded();
 $order->get_item_count_refunded();
 $order->get_total_qty_refunded();
 $order->get_qty_refunded_for_item();
 $order->get_total_refunded_for_item();
 $order->get_tax_refunded_for_item();
 $order->get_total_tax_refunded_by_rate_id();
 $order->get_remaining_refund_amount();
 // Get and Loop Over Order Items
 foreach ( $order->get_items() as $item_id => $item ) {
    $product_id = $item->get_product_id();
    $variation_id = $item->get_variation_id();
    $product = $item->get_product();
    $product_name = $item->get_name();
    $quantity = $item->get_quantity();
    $subtotal = $item->get_subtotal();
    $total = $item->get_total();
    $tax = $item->get_subtotal_tax();
    $taxclass = $item->get_tax_class();
    $taxstat = $item->get_tax_status();
    $allmeta = $item->get_meta_data();
    $somemeta = $item->get_meta( '_whatever', true );
    $product_type = $item->get_type();
 }
 // Other Secondary Items Stuff
 $order->get_items_key();
 $order->get_items_tax_classes();
 $order->get_item_count();
 $order->get_item_total();
 $order->get_downloadable_items();
 $order->get_coupon_codes();
 // Get Order Lines
 $order->get_line_subtotal();
 $order->get_line_tax();
 $order->get_line_total();
 // Get Order Shipping
 $order->get_shipping_method();
 $order->get_shipping_methods();
 $order->get_shipping_to_display();
 // Get Order Dates
 $order->get_date_created();
 $order->get_date_modified();
 $order->get_date_completed();
 $order->get_date_paid();
 // Get Order User, Billing & Shipping Addresses
 $order->get_customer_id();
 $order->get_user_id();
 $order->get_user();
 $order->get_customer_ip_address();
 $order->get_customer_user_agent();
 $order->get_created_via();
 $order->get_customer_note();
 $order->get_address_prop();
 $order->get_billing_first_name();
 $order->get_billing_last_name();
 $order->get_billing_company();
 $order->get_billing_address_1();
 $order->get_billing_address_2();
 $order->get_billing_city();
 $order->get_billing_state();
 $order->get_billing_postcode();
 $order->get_billing_country();
 $order->get_billing_email();
 $order->get_billing_phone();
 $order->get_shipping_first_name();
 $order->get_shipping_last_name();
 $order->get_shipping_company();
 $order->get_shipping_address_1();
 $order->get_shipping_address_2();
 $order->get_shipping_city();
 $order->get_shipping_state();
 $order->get_shipping_postcode();
 $order->get_shipping_country();
 $order->get_address();
 $order->get_shipping_address_map_url();
 $order->get_formatted_billing_full_name();
 $order->get_formatted_shipping_full_name();
 $order->get_formatted_billing_address();
 $order->get_formatted_shipping_address();
 // Get Order Payment Details
 $order->get_payment_method();
 $order->get_payment_method_title();
 $order->get_transaction_id();
 // Get Order URLs
 $order->get_checkout_payment_url();
 $order->get_checkout_order_received_url();
 $order->get_cancel_order_url();
 $order->get_cancel_order_url_raw();
 $order->get_cancel_endpoint();
 $order->get_view_order_url();
 $order->get_edit_order_url();
 // Get Order Status
 $order->get_status();
 // Get Thank You Page URL
 $order->get_checkout_order_received_url();