Go down and check coupons out. Remember to check price history if it is available. What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
XTAR Battery Charger 18650 Power Bank Fast Charge Type C QC3.0+PD3.0 Quick Charging 18700 20700 21700 Batteries PB2S Powerbank – Red
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood.
Link: Banggood product page
Price: $-3
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 and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGcharles03, BGd57765
(these coupons are old, so probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for XTAR PB2S Battery Charger 18650 Power Bank.
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)).