Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Europe 
. I don’t know if this is a good price – number of records in my database is too low!
Link: Banggood product page
Coupon (31.98 USD): BGGutscheine
Coupon (32.33 USD): BG8ReviTrage
Coupon (32.33 USD): BGcoupon8off
(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): BG126161, BGSTHO15, BGHONEY2110, BGSHOM15, 13f142, 6GSGIT, BGSmart6, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, BG15Sonoff, Cuponation9
(there’s a little possibility that old coupon will work)
Price history and price alert
Well, you won’t see price history chart, coz we have only 1 database record for this item (and price was 20.42 USD).
You can set price alert (for Banggood).