If your customers choose a delivery date at checkout, Shopify stores it as a note attribute on the order.
Enter the name of that note attribute here, and Junipeer will pick up the delivery date from it.
Good to know
Leave it empty if you don't use delivery dates.
Also set Shopify Delivery Date format so the date is read correctly.
Type each value exactly as your webshop sends it – same spelling and same upper/lower case. A value that doesn't match is skipped without an error, and the default is used instead.