private async void BtnEditEmployee_Click(object sender, RoutedEventArgs e)
        {
            UserApiService service = new UserApiService();
            int            userid  = 0;

            try
            {
                RefreshLabels();
                if (dgShowEmployees.SelectedItem != null)
                {
                    userid = (dgShowEmployees.SelectedItem as UserVM).Id;
                }
                string req = await service.UpdateAsync(new UserUpdateVM { Id = userid, Name = txtName.Text, Email = txtEmail.Text });

                MessageBox.Show("Працівник відредагований успішно.");
                txtEmail.Text = "";
                txtName.Text  = "";
                FillDG();
                dgShowEmployees.SelectedItem = null;
            }
            catch (WebException wex)
            {
                ShowException(wex);
            }
        }