Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in Hong Kong. So I have checked for active coupons (all category coupons and old ones), but there was no working coupon in Banggood.
Link: Banggood product page
Price: -3 USD
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
Old coupons (from the oldest to the newest): 2022ACTIESNL, BG17022b, BG3c4ec9, Terence, BGa9315f, BG2f426e, 2203ActiesNL, BGcd5950, CouponsdePC, BGbbcf62, BG0ec886, BGcfa5f1, BG43b579, tRaDetRaCKeR, BG48e14f, 8wEbgaInS5, BG0f0a22, hoNEYbGdeAlS
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Price history (for all/most countries) for Beelink GTR4 Ryzen9 4900H 32/500GB Mini PC is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).