Using Proof Key for Code Exchange (PKCE) in ADFS for Windows Server 2019

Program.cs

using IdentityModel;
using System;
using System.Security.Cryptography;
using System.Text;

namespace ADFS_PKCE_Core
{
    class Program
    {

        // https://www.scottbrady91.com/OpenID-Connect/ASPNET-Core-using-Proof-Key-for-Code-Exchange-PKCE
        static void Main(string[] args)
        {
            //var codeVerifier = CryptoRandom.CreateUniqueId(32);
            var codeVerifier = "1qaz2wsx3edc4rfv5tgb6yhn1234567890qwertyuiop";

            string codeChallenge;
            using (var sha256 = SHA256.Create())
            {
                var challengeBytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(codeVerifier));
                codeChallenge = Base64Url.Encode(challengeBytes);
            }

            Console.WriteLine("codeVerifier " + codeVerifier + "\n");
            Console.WriteLine("codeChallenge " + codeChallenge + "\n");

            Console.ReadLine();
        }
    }
}

https://medium.com/the-new-control-plane/using-proof-key-for-code-exchange-pkce-in-adfs-for-windows-server-2019-a457172e28c3