Here is a simple and easy method to duplicate any items in Cyberpunk 2077, you can duplicate any items such as weapons, materials, mods, etc.
Guide to Duplication Glitch
Keep in mind that duplicating items will cost you money.
In this method you simply need to go by any droppoints around the map. when you get there you should press to keys at the same time to glitch the droppoint.
First sell only one of whatever item you want to duplicate, then you should Press ESC + R at the same time. if you do it correctly you will get sell menu but with transparent background like the picture below.
Now you can buy infinite amount of watever you sold.
I also made a small video to show you how its done aswell.