How to Auto populate the location for each item line in purchase order?

Hi

We are using inventory multi-location and main locations with bins . when we populate the Purchase Order with items, how can we auto-fill the location for each item line based on the location completed in the body of the PO. see screenshot below

This is important as when we run the stock pricing with on order report, the quantity does not display if this location is not populated on the purchase order. also, the 'on order' quantity is not displayed in the item record.

Thank you