According to MS doc,

when invoices are imported, the invoice lines are automatically generated, based on information on the corresponding purchase order, which means that product receipts must be processed before vendor invoice headers are imported into the system so the lines from product receipts can be automatically populated into the vendor invoices.

Since it's by design that there's no batch job running in the background for this process, it's not possible to import the invoice header first then wait for the lines to be created from product receipt which comes later, while this is a typical business scenario where invoices are sent electronically/via email – which will often get long before a delivery is made.

We request to have a process automation/ background batch job for this functionality to make it adapt with real business scenarios.