Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (5.49 USD): BGdaa649
Coupon (12.99 USD): BG0af381
(CouponsFromChina.com tip: put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGIMILAB20W, BgcLuBofErtA10, BG20CHARGER, BGAFF10OFF, BGMBCBLE, BGCuponation10, 13f142, BGHONEY2110, BGa5ac2b, BG3af60d, BANGGOODSD, 6GSGIT, BGCCARG, BG7dfab7, BGe22349, BGea864b, BGBFS43
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for IMILAB 20W USB-C PD Charger.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).