Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Europe. You can get coupon down below.
Link: Banggood product page
Coupon (1973.99 USD): BG00c906
(CouponsFromChina.com tip: apply it in your cart 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): 7bcdf9, BGEBSC15, BG10OFFAFF1, 6GSGIT, BG01b49c, 00c906
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for RICH BIT TOP-016 9.6AH 48V 500W Electric Bike.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).