Discount Codes on Order Items

[DevSiopen]

Hi there!

First of all, I should mention that I’m using OrdersOperationQueryBuilder to build my query.

I’m having a bit of trouble retrieving the discount codes for the order lines.
Specifically, I’ve read online that the discount code isn’t listed on the order lines themselves, only the index.
So I’m trying to load the index as shown in the screenshot:

It returns this error:

Could you please tell me how to resolve this?

Many thanks!

[DevSiopen]

I ran several tests and resolved the issue by adding ‘.AddField(“__typename”)’.
However, I haven’t encountered any cases where multiple discounts apply to different items.

Is it correct to load the line-level discount index and then match it against the header-level one? (by loading DiscountCodes into the header)

Thanks!