If the e-IFU is built-in to the device, then the QR code probably is not going to work. Keep in mind, the QR code or other method is an option, not a requirement.
Furthermore, if your product is offered in the EU, then you must consider REGULATION (EU) 2021/2226, which requires that regardless of how to provide access to eIFU, you must also publish the eIFU on your website.