Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment.
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): BgcLuBofErtA10, BGJAFR493, BGAFF10OFF, BGCuponation10, 13f142, BGHONEY2110, BGAPSX493, BG23ac11, BGHealth10D, 2022ACTIESNL, BGHB218, BG311f53, BGMCL23, BG0a5564, BGacddd9, BG127436, BGHECARE1, BG4ee866, BGHOM111, Cuponation9, BG75597c
(these coupons are old, so probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for BOXYM Bluetooth Pulse Oximeter.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).