How use QR code to check validity of Invoice

I am able to insert QR code on invoice template(so643000) with any fields i need with no challenge.

I have a requirement from customer to use the QR code to check if invoice exist in database for the customer, date and amount. If exist the QRCode should return “Valid Invoice for Customer “ABC”, Date “23/04/2024”, Amount “USD500”. If invoice cannot be found the QRCode should show “Invalid Invoice”

Any help appreciated