List Sales Totals for all Sales Regions (via the Territories table using 4 joins) with a Sales Total greater than 1,000,000. Use rounding or FORMAT to present the numbers?

Using the Northwind Database I need to run a query that list Sales Totals for all Sales Regions via the Territories table using 4 joins with a sales Total greater than 1,000,000. I am new to SQL and this is what I think the query would look like but I am not sure if I am using the right data and tables or joining them correctly. Can someone just help me and tell me the fields I need and how I should be joining them to get the right result.

SELECT SUM(od.Quantity * od.UnitPrice) total_sales FROM [Order Details] od
INNER JOIN Orders o ON o.orderID = od.orderID
INNER JOIN EmployeeTerritories et ON et.employeeID=od.employeeID
INNER JOIN Regions t ON t.regionID = et.regionID
INNER JOIN Territories t ON t.regionID = r.regionID