How to load Purchase Order Freight Charges on Item Cost

Hello All

We have a requirement to load the PO freight charges on the Item Cost

Business Case - We have an agreement with a transporter who takes care of our logistics. Now, this transporter completes all the shipment and send us monthly invoices based on the number of shipments it has completed for the given month.

Now the issue is, we have already created the receipts of these PO and these freight charges were not added at the time of receipt. However we would like to add the freight charges on the items as the item cost whenever we receive these bills.