Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in Hong Kong. As you can see I didn’t find any active coupon for this product right now…
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): BGABU, BGBUES, band10, BGHU0280, BGAMBU, BGABU64, BGJPABU, BGCuponation10, BGABipU, BGeb95e2, BG514c8f, BG975526, BG428944, BG2fcf6a, BGbbcee9, BGdf2e3a, BGWRIBAND10
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Amazfit Bip U Smart Watch Global.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).