REST API - Order Creation - Setting 'Order Notes' & Custom Field Values


I am creating orders using the ‘Create an Order’ REST API endpoint. I need to set the “Order Notes” field as well as a custom field on the orders. Based on a previous community post, it appears the REST API does not support the Order Notes field or custom fields. However, that post is a few years old, so I wanted to confirm if that is still the case.

As a side note - when I retrieve an order via the REST API, I get a “notes” field in the response but it doesn’t appear to be the “Order Notes” field, and I am curious as to which field “notes” represents.