How do you get the orders data report from MWS to match the GUI reports?



We are pulling in the GET_FLAT_FILE_ALL_ORDERS_DATA_BY_ORDER_DATE into our data warehouse to eventually pull through to Power BI. We’re finding that the Item Sale Price is lower than what’s being reported in the Sales and Traffic report (Ordered Product Sales) within the seller central business reports GUI. What pieces of information do we need in order to get this to match? Is it the GET_FLAT_FILE_RETURNS_DATA_BY_RETURN_DATE plus some combination of sales tax and…?

Thank you in advance for your help!