WIFI Digital Wattmeter EU Plug 220V is for $21.99 (in Banggood). Basically copy coupon, view price history or create e-mail price alert. You probably want to know what is the best price?
Latest price update (UTC time):
Weight: 160g, Working humidity: <80%, Power: MAX3680W, Accuracy: +1%, Wi-Fi frequency: 2.412 ~ 2.484 MHz, Dimensions: 133X76X73mm, Measuring voltage: AC85-265V, Date function: month/day, frequency: 50 / 60HZ, Material: ABS + PC, Type: Wifi version /Bluetooth version (optional), Plug type: EU plug, Energy Measurement range: 0 ~ 1999kWh, Power factor: 0-1.00PF, Measuring current: 0-16A Max16A, Working temperature: -10°C ~ +60°C degree, Security Type: WEP64 / WEP128 / TKIP / CCMP (AES), Wireless consumption: <0.3W, Model: S1W, Screen Type: 2.4inch TFT-LCD HD Display Panel Graphic 240´RGB´320 Dot-matrix
Banggood ($21.99)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. But wait a sec… Is it a good price? Hmmm, price is higher than average (which is $19.99 right now), so better set price alert down below…
Link: Banggood product page
Price: $21.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGGines, BG0dd754, BGTOOS729
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for WIFI Digital Wattmeter EU Plug 220V.
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)).