Bad encryption

Encrypt.cs

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

namespace EncryptPassword
{
    class Program
    {
        static void Main(string[] args)
        {
            var random = new Random((int)DateTime.Now.Ticks);

            Console.Write("Enter the password: ");
            var rawPassword = Console.ReadLine();

            ulong key = (ulong)random.Next(0, 65536);
            Console.WriteLine($"Secret key: {key}");

            string encryptedText = Encrypt(rawPassword, key);

            Console.WriteLine($"Encrypted:");
            Console.WriteLine(encryptedText);
            Console.ReadKey();
        }

        static string Encrypt(string rawText, ulong key)
        {
            string base64EncryptedText;

            // create a provider using the encryption key
            using (var provider = new DESCryptoServiceProvider
            {
                Key = BitConverter.GetBytes(key),
                IV = BitConverter.GetBytes(key)
            })
            {
                // get an encryptor from the provider
                var encryptor = provider.CreateEncryptor();

                // Convert the text from a string to bytes because the encryption algorithm works on byte arrays.
                var passwordBytes = Encoding.ASCII.GetBytes(rawText);

                // Use the encryptor to transform the block of bytes into 
                var encryptedBytes = encryptor.TransformFinalBlock(passwordBytes, 0, passwordBytes.Length);

                // convert the bytes to base64 text so we can store it in a text file
                base64EncryptedText = Convert.ToBase64String(encryptedBytes);
            }

            // return the generated encrypted password
            return base64EncryptedText;
        }
    }
}

Given that my encrypted password generated from the program above is:

FtAMuJQMsSDRBI+BEPEyow==

Find what my actual plain text password is. Note that the key I have selected is between 0 and 65535 inclusive to keep run-times short.