Use the Add Multiple Parts assistant to add multiple part lines from a list in one go. The parts displayed are parts registerred as Purchase Parts for the Supplier the Quick Purchase Order is regesterref for. Activate the part-/s in the list with the toggle option Add and set a qty for the part. When done, click OK and the part-/s will end up in the Quick Purchase Order.
Purchase Parts must have been created for the used supplier.
Purchase order is created and can be processed.