Aliexpress
Click here… to search for POCO M4 Pro 5G NFC 6/128GB Global on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Hong Kong. There is one great coupon!
Link: Banggood product page
Coupon (179.00 USD): BG5aa0d2
(CouponsFromChina.com tip: this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG69967e, BGfacd33, BG658e7b, BG38320c, BGfc0840, BG2e78ad, BGfcddbf, BG71b319, BG8e5dfc, MVC8SPRING, BG77f355, BGa60baf, BG14497b, BGe0b34e, BGd382ee, BGee410b, BG3112dd, BG843229, BGeb0a68, BG7ec558, BG2c4b72, BGcb3b0f, BGROTTERG8, BGf3867b, BG71f5cf
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for POCO M4 Pro 5G NFC 6/128GB Global.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).