private async void OnLoginButtonClicked(object sender, EventArgs e)
        {
            try
            {
                LoginViewModel services        = new LoginViewModel();
                var            getLoginDetails = await services.CheckLoginIfExists(usernameEntry.Text, passwordEntry.Text);

                // var accesstoken = await services.CheckLoginIfExists(usernameEntry.Text, passwordEntry.Text);
                //Settings.AccessToken = accesstoken;


                if (getLoginDetails)
                {
                    await DisplayAlert("gelukt!", "U bent nu ingelogd", "Ok");

                    LoggedinUser.Username    = usernameEntry.Text;
                    LoggedinUser.Password    = passwordEntry.Text;
                    LoggedinUser.AccessToken = usernameEntry.Text + ":" + passwordEntry.Text;


                    await Navigation.PushModalAsync(new RootPage());

                    // await RootPage.ChangeLoginButton();
                }
                else
                {
                    await DisplayAlert("Inloggen mislukt!", "Gebruikersnaam en/of wachtwoord niet correct", "Ok");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
            }
        }