Note: True "QR Codes" as we know them (square matrix barcodes) were not the primary delivery method. However, the community has since reverse-engineered the save structure, allowing modern fans to create actual printable QR codes that inject content via emulator save editors.
You cannot scan a QR code using a Nintendo Switch or an emulator webcam. You need original hardware or a specific setup. mario kart ds qr code
These methods give you more control and don’t rely on obscure QR links. Note: True "QR Codes" as we know them