From where is defaulting the invoice type (prepayment or standard) related to a (complex or standard

Hello guys,

I need help regarding one issue: from where is defaulting the invoice type (prepayment or standard) related to a (complex or standard) PO?

I know that is some setup that needs to be done when creating the PO, on the lines type. But, what is that setup exactly? In the Financing zone of the line setup if I Put something in the Advance field means that the invoice that will be created by the supplier (on iSupplier portal) will be an advance invoice?

Thank you,

Stefania