The QR code scanner works just fine.
For the money, it is very good, except that it has one problem.
Unfortunately, although it reads all QR codes, it does not have Greek language among the supported ones.
So there is a problem if you want to register QR codes that contain Greek characters. It will spit garbage into the data.
There is a way to fix it, but it is a bit difficult.
You will have to put it into virtual serial port mode (there are instructions, meaning you basically scan a code from the booklet) and you will have to write a program that translates the Greek characters it reads into Greek keyboard letters that it will "type". The easiest way is to write a program in AI (I used Google AI Studio in Python, which is free); I told it my problem and it made it for me in 5 minutes. Only you will have to tell the program at the end of the copy and paste of the data to use the key combination shift+ins because ctrl+v will not work since it is different if you have Greek language selected in Windows; also tell the program to press the enter button after each input but to wait 0.25 ms so the system does not get clogged up. Of course, with this method it will NOT work wirelessly, neither with RF nor with BT, only with cable, but for so little money I think we cannot complain.
I hope I helped.
Here is the link to my app if you want to run it, but you need to have Python installed and a couple of dependencies.

https://ai.studio/apps/f613ad4a-a6f5-4fc4-a55e-35ad24911690

In the window at the bottom it tells you what dependencies you need in Python and how to install them. Good luck.