I have attempted to import invoices via Excel where invoices may have multiple products lines by following what I believe to be the guidance of not putting certain data in the fields such as number, partner, etc...
Here is an example of the my test import in which multiple invoice are still created per product line.
| Partner | Number | Invoice/Bill Date | Due Date | Journal | Invoice Lines/Product | Invoice Lines/Quantity | Invoice Lines/Unit | Invoice Lines/Unit Price |
| Client 1 | 1004 | 9/1/22 | 9/1/22 | Sales | Product 1 | 1 | Units | 250.00 |
| Sales | Product 2 | 1 | Units | 75.00 |
