Fetch delivery date from sales order to sales invoice


I want to fetch the delivery date from sales order item to sales invoice item.
I have created custom field in sales invoice Item doctype,named delivery date

as shown in first picture there is delivery date field in sales order, with date .

there is second picture of sales invoice of sales order where delivery date is custom field added in table i want the date from sales order to sales invoice.

kindly suggest the custom script
i have tried frm.add_fetch() it does not work.

thank you


Check this: Fetching Data from a Document

just use the same field-name in both documents and have “no copy” unchecked for the original field in the Sales Order Child Table.