using System;

using OtpNet ;

public class Program

{

    public static void Main()

    {

        GenarateTOTP();

    }

    public static void GenarateTOTP()

    {

        var key = "UHVudG9zMTYwMzQwMDE1Mzk0NDcyNjA0MTUxODFEOUEtOTAyQy00NTA5LTg1ODQtMDUwMTI0OEJERDdBMjk0NDcyNjA0Q29sb21iaWE=";

​

        Console.WriteLine(CodeCalculation(key));

    }

    private static Totp LoadTotp(string secretKey)

    {

        var base32Bytes = Convert.FromBase64String(secretKey);

        return new Totp(base32Bytes, step: 60, totpSize: 4);

    }

    public static string CodeCalculation(string secretKey)

    {

        var totp = LoadTotp(secretKey);

        var stringDate = "2020-10-24 14:05:00";

        var dateTime = DateTime.Parse(stringDate).AddHours(5);

        //var dateTime = DateTime.UtcNow;

        Console.WriteLine(dateTime);

        return totp.ComputeTotp(dateTime);

    }

}