To create a receipt with a QR code for your rock concert, you'll need to include essential information such as the event details and a unique identifier for each attendee. You can generate a QR code using various online tools or libraries. For example, if you're using Python, you can use the qrcode library. 

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Configure QR Codes on Tickets:

• Ensure the QR Code feature is enabled in the event tickets. This can be done in the Event > Settings menu.
• Customize the receipt or ticket template to include the QR code. Each code will be unique and linked to the attendee’s registration.

After a customer purchases a ticket, Odoo automatically sends a confirmation email with the receipt.

The ticket will include the QR code that identifies the attendee