Custom field in invoice line item

I need to implement fields in invoice line item … field like “colli - box number”, "gross weight " and “netto weight” . I set up one template ( see attach) but I need also to set up imput interface for this field .
How can I do this.

It’s not currently possible to set up custom fields as columns on individual line items within sales invoice.

At some point in future, I will probably add this.