Outlays are for company one-off purchases (enstaka inköp) and are not part of the supplier purchasing flow.
Only the date, what you paid and the receipt. Everything else takes the company's outlay defaults from Settings.
Enter what you paid - VAT and the net amount are calculated - or the net amount if that is what the invoice shows.
Who you bought from and what kind of purchase it was. Fields that do not apply are hidden as you choose.