private void btn_submit_Click(object sender, RoutedEventArgs e)
        {
            Authentication.Authentication auth   = new Authentication.Authentication();
            GamePlay.GameRounds           rounds = new GamePlay.GameRounds();
            auth.UserName    = txt_Username.Text.Trim();
            auth.Password    = txt_oldPswd.Password.ToString().Trim();
            auth.NewPassword = txt_newPswd.Password.ToString().Trim();

            string stus = auth.ChangePassword();

            if (stus == string.Empty)
            {
                var res = MessageBox.Show(stus, "Error Information", MessageBoxButton.OK, MessageBoxImage.Error);
                auth.error_flag = string.Empty;
                if (res.ToString() == "OK")
                {
                    txt_Username.Text    = string.Empty;
                    txt_oldPswd.Password = string.Empty;
                    txt_newPswd.Password = string.Empty;
                    this.Show();
                }
            }
            else
            {
                MessageBox.Show(stus, "Information", MessageBoxButton.OK, MessageBoxImage.Information);
                this.Close();
            }
        }
        public async Task <IActionResult> ChangePassword([FromForm] string userName, [FromForm] string password, [FromForm] string confirm, [FromForm] string currentPassword)
        {
            if (password != confirm)
            {
                return(Conflict("Пароли не совпадают"));
            }

            var user = await _auth.ChangePassword(userName, password, currentPassword);

            if (user == null)
            {
                return(NotFound($"\"{userName}\" не найден"));
            }

            return(Ok(user));
        }