Hi,
Thank you for reaching out to us! I hope you’re doing well.
There’s already a way to scan QR Codes to check in attendees on the events. You may want to take a look at the article on how to use QR Codes.
With regards to your submission to UserVoice, it is highly appreciated 🙂 We try to hear our community as much as we can in order to make the best products as possible. I’d recommend you to find other users with the same need and ask them to upvote your idea.
If you urgently need help with this and it is something you require for a project, however, you may instead wish to consider working with a suitably skilled developer or designer who can offer the additional level of support you require to create an extension.
Best,
Juan.