How can I show Keyboard buttons in a Telegram bot integrated with api.ai?

Question

I have a sample Telegram Bot that I have integrated in my api.ai account. I wanted to display Keyboard buttons just like below but it seems that api.ai is only sending the main text reply to telegram. Any idea how can I achieve on what I have just describe above? Please advise for directions and/or solutions. Thanks!

I have a Fulfilment webhook url that returns this json when my sample Intent is invoked

{
  "id": "af681b42-9ced-4f8f-ab0c-0559b210dc1a",
  "timestamp": "2016-07-15T01:47:30.896Z",
  "result": {
    "source": "agent",
    "resolvedQuery": "Hello",
    "action": "show-main",
    "actionIncomplete": false,
    "parameters": {},
    "contexts": [],
    "metadata": {
      "intentId": "e477976e-2412-4066-b320-48d7dedd5dfe",
      "webhookUsed": "true",
      "intentName": "Adobo"
    },
    "fulfillment": {
      "speech": "Hello world!",
      "source": "index.php",
      "data": {
        "chat_id": 1,
        "text": "hi there",
        "parse_mode": "HTML",
        "reply_markup": {
          "keyboard": [
            "A1",
            "A2"
          ],
          "one_time_keyboard": true,
          "resize_keyboard": true
        }
      }
    },
    "score": 1
  },
  "status": {
    "code": 200,
    "errorType": "success"
  },
  "sessionId": "4cb02864-9925-4d4c-a0f1-14dbab44add7"
}

I have added in the json format for reply markup keyboard under "data".

Answer 1

Were you able to send text alone (without the keyboard) before?

I think it's a syntax error. The "keyboard" field is supposed to be an array of arrays. Please try replacing that field with the below snippet.

"reply_markup": {
    "keyboard": [
        ["Day", "Week", "Month"],
        ["Users", "Retention"],
        ["sessions", "Events"],
        ["Back"]
    ],
    "one_time_keyboard": true,
    "resize_keyboard": true
}