Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
Coupon (100.57 USD): BG589b2e
(CouponsFromChina.com tip: this code has to be applied 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): BG00c906, BG04ab30, ADMITAD2212, 2022ACTIESNL, BGAlerabat1, Terence, 8Couponsde, MVC8SPRING, tRaDetRaCKeR, 8wEbgaInS5, BGHU2104, pROMo8cuPoN, hoNEYbGdeAlS, BGJUNEGSG9, BG046309, BG8ReviTrage, Cuponation9, BgGoodie9, BGcoupon8off, BGGutscheine, TTBLACK5
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Tuya WiFi Fingerprint Smart Door Lock is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).