I have checked all old coupons and price is 18.99 USD for 3.4A EU (in Banggood). Go down and check coupons out. Remember to check price history if it is available. Best price?
Latest coupon and price update (UTC):
Banggood (18.99 USD)
Banggood warehouse is located in China. There are no coupons available at this moment in Banggood. Low/high price? From what I can see this price is higher than average price (13.99 USD).
Link: Banggood product page
Price: 18.99 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGLD6u1, 502C6B, BGLDNIO27, AFfbG10, LDNIO2, 20MWC, BGVDay10%off, BGMPB2020, bGhOnEy10, BGXMI15, BG20CHARGER, BGMBCBLE, BGAFF10OFF, BGCuponation10, 13f142, BGHONEY2110, BGe8a34b
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
Click here… to search for LDNIO 5V 3.4A EU Plug Charging Socket SE3631 on Aliexpress
Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for LDNIO 5V 3.4A EU Plug Charging Socket SE3631.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).