These instructions use qrcode.js from the repo.

Adding QR codes to the 2FA configuration page If the default templates enforced 'local' 2FA then users would be required to satisfy two 2FA approaches, which is not a commonly used scenario. Consider, for example, the Microsoft authentication provider requires a hardware key or another 2FA approach. External logins are protected by whatever mechanism the external login provider provides. Two-factor authentication does not happen using an external authentication provider, such as Google or Facebook. This document will guide you through adding QR code generation to the 2FA configuration page. QR code generators ease the setup of 2FA. The ASP.NET Core web app templates support authenticators, but don't provide support for QR code generation. Typically an authenticator app is installed on a smartphone. An authenticator app provides a 6 to 8 digit code which users must enter after confirming their username and password.

Two factor authentication (2FA) authenticator apps, using a Time-based One-time Password Algorithm (TOTP), are the industry recommended approach for 2FA. ASP.NET Core ships with support for authenticator applications for individual authentication.

Authenticator app qr code