Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon 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): BG00c906, BGc1186a, BGb8b217, BG4ff9f4, BGHU2211, Cuponation9, BG0f11c0, BgGoodie9, BG8OFFCOUPON
(these coupons are old, so probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi Redmi Curved 30-inch Gaming Monitor 200Hz? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).