Good evening Sentosa and welcome back!
Thank you for reaching out to us.
We are sorry to hear about the fact that you could not find clear instructions on our QR codes.
I would love to help you with this topic.
You are almost there. For the scan functionality to work as a check-in, you absolutely need to be logged in to the website with a proper account.
Of course site admin works but you could customize the role required with a plugin such as Members.
Let me know how that goes.
Best regards,
Geoff B.