How do you disable TOTP authentication when using identity core authentication

Question

I have a net standard 6 mvc application that utilizes asp.net core identity for authentication. I want to set up 2fa but I don't want to use an authenticator installed on the end users smart phones. I want to stick with sms and email messaging where a 6 digit code is provided for authentication. The issue I am facing is that cannot disable TOTP. I think that using AddTokenProvider in place of AddDefaultTokenProvider in program.cs will work but I can't find suitable literature on how to implement a custom 2fa token provider. Please let me know if anybody has come across a fix for using a custom token provider for 2fa login.

Answer 1

Hope the following document gives you some idea although it is for ASP.NET Core 1.1:

Two-factor authentication with SMS in ASP.NET Core
https://learn.microsoft.com/en-us/aspnet/core/security/authentication/2fa?view=aspnetcore-1.1