List the name of the customer with the most number of order quantity from 2018 to 2020.
name of customer refers to Customer Names; from 2018 to 2020 refers to OrderDate between '1/1/2018' and '31/12/2020'; most number of order quantity refers to Order Quantity = 8
SELECT T1.`Customer Names` FROM Customers AS T1 INNER JOIN `Sales Orders` AS T2 ON T2._CustomerID = T1.CustomerID WHERE T2.OrderDate LIKE '%/%/18' OR T2.OrderDate LIKE '%/%/19' OR T2.OrderDate LIKE '%/%/20' ORDER BY T2.`Order Quantity` DESC LIMIT 1