The refund request.
amountobject<amount>OptionaltotalstringRequiredsubtotalstringOptionalNote: For an order authorization or capture, you cannot include the subtotal parameter.handling_feestringOptionalNote: For an order authorization or capture, you cannot include the handling_fee parameter.shipping_discountstringOptionalNote: For an order authorization or capture, you cannot include the shipping_discount parameter.insurancestringOptionalNote: For an order authorization or capture, you cannot include the insurance parameter.