let
Source = Excel.CurrentWorkbook(){[Name="Sales_Data3"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"OrderDate", type date}, {"Region", type text}, {"City", type text}, {"Category", type text}, {"Product", type text}, {"Quantity", Int64.Type}, {"UnitPrice", type number}, {"TotalPrice", type number}}),
#"Inserted Year" = Table.AddColumn(#"Changed Type", "Year", each Date.Year([OrderDate]), Int64.Type),
#"Inserted Month" = Table.AddColumn(#"Inserted Year", "Month", each Date.Month([OrderDate]), Int64.Type),
#"Grouped Rows" = Table.Group(#"Inserted Month", {"Year", "Month"}, {{"Total", each List.Sum([TotalPrice]), type nullable number}}),
#"Sorted Rows" = Table.Sort(#"Grouped Rows",{{"Year", Order.Ascending}, {"Month", Order.Ascending}})
in
#"Sorted Rows"