Response cards not showing -Amazon lex

I have created a lex chatbot and integrated it into website .Its working fine.I got to know that I have to invoke response cards from lambda .I did that too.Also,I enabled repsonse card checkbox in lex console.After all this,I am not able too see the buttons in the website.Is there any other way to display the buttons other than response cards?

Below is the code:Here,after the fulfillment,I have given the response card which means that after the message "Hey your ticket has been raised",the buttons will be displayed.This displays in lex test chatbot.

import json
import logging
import re
import http.client
import mimetypes

logger = logging.getLogger()
logger.setLevel(logging.DEBUG)


def close():
    val=  {
             "dialogAction":
            {
                "fulfillmentState":"Fulfilled",
                "type":"Close",
                "message":
                 {
                     "contentType":"PlainText",
                     "content":"Hey your ticket has been raised"
                 },
                'responseCard': {
                'version': '0',
                'contentType': 'application/vnd.amazonaws.card.generic',
                'genericAttachments': [
                    {
                    'title': 'title1',
                    'subTitle': 'subtitle',
                    "buttons":[ 
                     {
                        "text":"button 1",
                        "value":"value 1"
                     },
                     {
                        "text":"button 2",
                        "value":"value 2"
                     },
                     {
                        "text":"button 3",
                        "value":"value 3"
                     }
                        ]
                    }
                    ]
                                 }
                    }
                }
    print(val)
    return val
    

def lambda_handler(event, context):
   
    slots = event['currentIntent']['slots']
    empidemployee= event['currentIntent']["slots"]["empidemployee"]
    latestdesc= event['currentIntent']["slots"]["latestdesc"]
    latestservice= event['currentIntent']["slots"]["latestservice"]
    latestimpactvalue= event['currentIntent']["slots"]["latestimpactvalue"]
    latesturgency= event['currentIntent']["slots"]["latesturgency"]
    basicinfo=event['currentIntent']["slots"]["basicinfo"]
    val=close()
    return val