Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Well, there is one coupon available right now.
Link: Banggood product page
Coupon (39.99 USD): BGHKLP2
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): AFfbG10, BGXMNECK, BGXMNE99, 502C6B, BGBFAFF2019, BGCITYADS2019, BGVDay10%off, EARSP11, BGMPB2020, BGAFF10OFF, bGhOnEy10, Email5, BGSS10%SW, bgshOOp10, BGELIG0920, BG11SHOP, BG11PP7
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for Xiaomi LYXQEJ03JY Collar Neckband Bluetooth Earphones.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).