Basically copy coupon, view price history or create e-mail price alert. Do you want to know what the best price is?
Hey+ B1800(Internation Version), Android 4.4 / iOS 9.0 or above, BT4.0 or above, Size: 0.95 Inch, Resolution: 240*120, Battery Capacity: 120mAh
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($27.87): BGXMHJ
2. ($30.59): AFfbG10
3. ($30.59): band10
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): F8AAF1, f8aaf1, TTxBG10, e2bcea, 502C6B, bghey, BG3CSUM, BGHEYPL, BGsaldihey, bghj, BGBFAFF2019
(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 Hey Plus B1800 Smart Watch is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).
Thank you!
Coupon 1 ($31.79): BGHEYPL cannot be used. It said selected countries only. I’ve tried Canada and the States but neither worked.
Sorry. You can create price alert though. Maybe there will be new coupon that will work in Canada