The default number of order lines per order is 128 however this can go up to a maximum of 255. You can have any quantity of product per order line.
This setting can be changed from the Neto dashboard by navigating to Setup & Tools > All settings & tools.
Click on the Other tab in the left hand side navigation menu and click Advanced Configuration.
In the name query, type: MAX_ORDERLINES and click Apply Filter.
Click on the MAX_ORDERLINES search result and set the value up to 255 and click Save Changes.