public InitialQuestions(string dialogId, IEnumerable<WaterfallStep> steps = null)
        : base(dialogId, steps)
    {
        AddStep(async (stepContext, cancellationToken) =>
        {
            var cardAttachment = CreateAdaptiveCardAttachment(_cards);
            var reply = stepContext.Context.Activity.CreateReply();
            reply.Attachments = new List<Attachment>() { cardAttachment };
            await stepContext.Context.SendActivityAsync(reply, cancellationToken);

            // how can i wait for user to click submit before going to next step?
            return await stepContext.NextAsync();

            // return await stepContext.PromptAsync(
            //   "textPrompt",
            //   new PromptOptions
            //   {
            //       Prompt = MessageFactory.Text(""),
            //   },
            //   cancellationToken: cancellationToken);

        });

        AddStep(async (stepContext, cancellationToken) =>
        {
            // next step
        });
    }

     private static Attachment CreateAdaptiveCardAttachment(string filePath)
    {
        var adaptiveCardJson = File.ReadAllText(filePath);
        var adaptiveCardAttachment = new Attachment()
        {
            ContentType = "application/vnd.microsoft.card.adaptive",
            Content = JsonConvert.DeserializeObject(adaptiveCardJson),
        };
        return adaptiveCardAttachment;
    }

{
  "type": "AdaptiveCard",
  "body": [
    {
      "type": "TextBlock",
      "text": "What is your Occupation?"
    },
    {
      "type": "Input.Text",
      "id": "SimpleVal",
      "placeholder": "Occupation"
    },
    {
      "type": "TextBlock",
      "text": "Are you married? "
    },
    {
      "type": "Input.ChoiceSet",
      "id": "SingleSelectVal",
      "value": "true",
      "choices": [
        {
          "title": "Yes",
          "value": "true"
        },
        {
          "title": "No",
          "value": "false"
        }
      ],
      "style": "expanded"
    },
    {
      "type": "TextBlock",
      "text": "When is your birthday?"
    },
    {
      "type": "Input.Date",
      "id": "DateVal",
      "value": ""
    }
  ],
  "actions": [
    {
      "type": "Action.Submit",
      "title": "Submit",
      "data": {
        "id": "1234567890"
      }
    }
  ],
  "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
  "version": "1.0"
}