Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (46.74 USD): BGSTHO15
Coupon (49.49 USD): BGAFF10OFF
(CouponsFromChina.com tip: apply it 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): BGXIAOMO, BGXM45D, AFfbG10, BGM1145D, BGBFAFF2019, BGMX45, BGCITYADS2019, BGMK44, BGWK39X, BGXMO39, BGHOMEG12, BGSAMRTH, 7d18f7, BgcLuBofErtA10, BGXMDBH, BG15SH12
(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 Xiaomi Xiaomo AI 1080P Video Doorbell is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).