Add attachment to line items

Hi,

We are using Unifier 23.12.16.1, we have API to add line items, and add attachment to these line items.

When we try to run the API, it returns 200, as it is successful, but at the end the attachment is not in the line item.

Have you face this before ?

I can't find in the integration documentation where it says clearly what we can ans what we can't.

Regards,

Mahisha