You can use the formulas below in the Calculated Fields to extract the total duties amount in the shop's currency from the Shopify order:

Original Total Duties (Entire order)

get_attribute_value({{ original_total_duties_set.shop_money }}, "amount")

Current Total Duties (Entire order; reflects order edits, returns, and refunds)

get_attribute_value({{ current_total_duties_set.shop_money }}, "amount")

Lineitem Total Duties

get_total(get_attribute_value(get_attribute_value({{ line_items.duties }}, "price_set", recursive=False, return_raw_results=True), "shop_money", recursive=False, return_raw_results=True), "amount")