using System;

public class Program

{

    public static void Main()

    {

        var dt = DateTime.Parse("2021-04-28T06:45:49.000Z").ToUniversalTime();

        var korean = TimeZoneInfo.ConvertTimeFromUtc(dt, TimeZoneInfo.FindSystemTimeZoneById("Korea Standard Time"));

        // Note this server seems to have UTC time as time zone, so this would always be the same as local time.

        Console.WriteLine("UTC Time: {0}", dt.ToString());

        Console.WriteLine("Local Time (depentent on computer): {0}", dt.ToLocalTime().ToString());

        Console.WriteLine("Korean time, always in korean time: {0}", korean.ToString());

    }

}