Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Hong Kong. There are no coupons for this product in Banggood.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG6521fe, BGfdd322, BG92efcf
(there’s a little possibility that old coupon will work)
Price history and price alert
Check out price history chart (for all/most countries) for Alldocube Stream Book 13.5 inch N4020 8/512GB Notebook.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).