Hello,
You need to use the Item Wise Tax Template.
Taxes are fetched from the Item, not the HSN Code though you can update taxes from the HSN Code.
In sales transactions like Quotation, Sales Order, and Sales Invoice the taxes on items are calculated as per the Sales Taxes and Charges Template selected. However, if some items have an Item Tax Template linked, then the taxes are calculated on those items as per the rates mentioned in the Item Tax Template instead of the rates mentioned in the Sales Taxes and Charges Template.
Documentation Link: Item Tax Template