protected override async void OnAppearing()
        {
            base.OnAppearing();

            var    tokenExists = Application.Current.Properties.ContainsKey(Constants.TokenName);
            string token;

            if (!tokenExists)
            {
                token = await BotService.GetToken();

                Application.Current.Properties[Constants.TokenName] = token;
            }
            else
            {
                token = Application.Current.Properties[Constants.TokenName].ToString();
            }

            string botWebViewUrl = "https://webchat.botframework.com/embed/AdventureWorksBotGAB19Munich?s=" + token;

            BotWebView.Source = botWebViewUrl;
        }
        protected override async void OnAppearing()
        {
            base.OnAppearing();

            var    tokenExists = Application.Current.Properties.ContainsKey(Constants.TokenName);
            string token;

            if (!tokenExists)
            {
                token = await BotService.GetToken();

                Application.Current.Properties[Constants.TokenName] = token;
            }
            else
            {
                token = Application.Current.Properties[Constants.TokenName].ToString();
            }

            string botWebViewUrl = $"{Constants.BotUrl}?s=" + token;

            BotWebView.Source = botWebViewUrl;
        }