public string GeneratePasswordHashUsingSaltOptimized()
{
var pbkdf2 = new Rfc2898DeriveBytes(passwordText, salt, iterations);
Span <byte> byteArr = stackalloc byte[36];
byteArr.AddRange(salt, 0, 16);
byteArr.AddRange(pbkdf2.GetBytes(20), 16, 36);
var passwordHash = Convert.ToBase64String(byteArr);
return(passwordHash);
}