One simpler use case would be to send a hubspot QR code to contacts who signed up on your form.
For each attendee, we can automate sending the QR code to the email of the attendee. If you have an event/booking system that generates a URL, that when visited will auto accepts/reject an attendee depending on its email/account. Otherwise a simple QR code generator API would be enough.
Ideally any reader should be able to read the QR code or else it will be an added cost having to install/develop a scanner solely for that. So, the key would then be to input in the QR code a link that does the intended logic.
Thoughts?