Error Creating Bill Payment when Bill record is created.

I am creating a workflow that will run when a Bill is imported. I have added a checkbox  (Import Flag) that will be checked during the import and unchecked from the input screen. The workflow is using the Transform Record action to create the Vendor Payment. When I test the workflow by checking the Import Flag checkbox from the Bill input form in NetSuite, I am receiving the error “You must enter at least one line item for this transaction.” How do I add the line item for the Vendor Payment record?

Thank you in advance.