Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (34.55 USD): BGAlerabatI
Coupon (35.33 USD): BGtorch2
(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): FIN67615, BGCONV, F46294, BGflashlight, BG10OFFAFF1, BANGGOODSD, BGTorch4, 00c906, BGtorch3
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for Convoy S16 SST40 20W Flashlight.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).