Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
Coupon (43.03 USD): BGOutlight10
(CouponsFromChina.com tip: you should apply the coupon 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): BGLED07
(probably won’t work, but you can try them out)
Price history and price alert
Check out price history chart (for all/most countries) for KLARUS EC20 SST20 1100lm Flashlight With 18650 Battery.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).