I am developing an events website that sends QR codes once someone register(to pay at the gate) or pays for an event on the website. I have discovered that buyers can share their QR codes and therefore use one ticket for multiple uses/entries into the event. How do I invalidate the link the QR code point to once it has been scanned and the link visited at least once once?
For reference, I am using this plugin https://wordpress.org/plugins/my-tickets/
Read more here:: Invalidate a visited link