Head over to reward.stampede.ai and login with your admin account.
Once logged in, you will be prompted with 2 options. For vouchers, click on 'Vouchers'.
You may be prompted to allow access to your camera, click on 'Allow.
Hover over the customer's QR code, please do allow a few seconds for Stampede to read the QR code.
Once scanned, you will see all the details of the voucher. If the voucher has been used, it will say "Voucher Code Invalid".