Aliexpress
Here are coupons that you can use.
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – DIGOO DG-DB1 433MHz Wireless Doorbell [EU] (-3 USD)
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I couldn’t find any coupon for this product on latest product update.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGSMOFF, BGDGASG, BGSAMRTH, BGDB109, BgcLuBofErtA10, BG15SH12, BGAFF10OFF, BGSTHO15, BG9b699e, BG2ef758, BG8d771c
(there’s a little possibility that old coupon will work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – DIGOO DG-DB1 433MHz Wireless Doorbell [EU] (-3 USD)
Price history and price alert
Here is price history (for all/most countries) for DIGOO DG-DB1 433MHz Wireless Doorbell.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).