ERPNext: Handling fields with array of keys/values

While trying to use the provided ERPNext node, I am struggling to figure out how the Field value for fields which require pairs of keys/values. For example, when choosing a Sales Order, what is expected the Items field value to look like? Using HTTP request node I can just add an array of the items with their specific attributes. The same goes for creating ERPNext node for creating an Item Attribute. I can use HTTP request to craft an Item Attribute Values array successfully but when I try to do the same with the ERPNext I keep getting error 417!.
Appreciate your inputs and thanks for the great work in improving and enriching n8n.

Did you try setting the value as an expression in the ERPNext node?

I did use expression. I pull data from Woocommerce, Erpnext documents require some key:value array for the items I mentioned above so I use an intermediate node to transform Woocommerce data into the required structure but without success.

Can you share the data Woocommercer is retuning and how it needs to be sent to the ERPNext? Are you sure the transformation was correct? How is the expression in the ERPNext node you are using right now?

@RicardoE105 I think I got the source of the problem, I entered the json content directly into the field value part and n8n added double quote to it. When I use the expression (yet work in progress), the double quotes are not added. I am trying to transform the products list into something that can be pushed to ERPNext but due to some product items have variations, I need to create some intermediary steps to extract and create the item attributes first before being able to create the items themselves.