Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (62.82 USD): BG651551
Coupon (62.82 USD): BGBRPL2
(CouponsFromChina.com tip: just apply this code 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): BGO2, BGBK15, BGBAK15, bGhOnEy10, 7d18f7, BGSS10%SW, bgshOOp10, BGELIG0920, BG11SHOP, BG4BW25, BGLOAC1, 13f142, BGa0b145, BGBuscape01
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Mifo O2 TWS Earbuds.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).