Some systems receive order discounts as order rows, just like a product. Enter the SKU (article number) to use for that discount row on orders and refunds.
For orders, you can use {voucher} to include the discount code. For example, with the code "RABATT10", discount_{voucher} gives the SKU discount_RABATT10.
Good to know
Leave it empty if the other system handles discounts on its own. For example, Fortnox uses "order_discount".
{voucher} only works for orders.