How to handle import duty tax?

Okay, so far I am trying to follow the freight-in method for cost allocation since it will be useful for shipping cost as well not just duties, according to the Manager guide, when there are a lot of inventory items in the purchase invoice, it is better to put the freight-in as an item at the end of the purchase invoice and select the inventory on hand account, but in order to have the freight-in as an item, I understand I should have created it first as an item.

I am following these steps, but after creating the shipping line invoice, and going to the original supplier’s invoice and adding the 2 fields as Manager suggests, the inventory on hand costs remain the same as if there was no freight charges.