You should take a look at LoginID: https://loginid.io/ https://loginid.io/ The idea of using QR codes is interesting too. The downside of WebAuthn is that the

You should take a look at LoginID: https://loginid.io/ https://loginid.io/ The idea of using QR codes is interesting too. The downside of WebAuthn is that the credentials generated by Touch ID/Face ID are associated with a single device. If you want to log in from somewhere else, it doesn't work. You could, however, use your QR code idea to have the user scan it from their enrolled device (e.g., phone) and then log them in.