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There are a number of free QR code generator websites, just look some up on google and put in your affiliate link and it should generate a QR code for you that you can print.

Ok I will search :)

Hopefully I can attract people by sharing them just the QR codes and quickly explaining about the game.
I can do this on the side when I am out with my "Students company"

You can use the free QR code online to create one for you https://4qrcode.com with different formats and styles then you scan it at https://4qrcode.com/scan-qr-code.php

I recommend this wonderful website and free to create your own QR Code at https://www.qr-code-scanner-online.com/qr-code-generator-free.php and you test it at https://www.qr-code-scanner-online.com/