How to populate INVOICE number field in Shiprush screen?

Have SR for SQL connected to a new Ablecommerce website under development.

I'm pulling data from the website's order database with an SQL script, but cannot figure out how to get the order number into the INVOICE field in Shiprush.

I'm able to import the order number into the REFERENCE field with this:

ac_Orders.OrderNumber as Reference

... how can I place the order # into the INVOICE field?