title: getting error "Action Error: no matching intent handler for: null" while accessing webhook URL
body: <p>I am trying to call webhook from dialog flow and not getting a response from webhook, the response I am getting from the response section, which I have put in intent. I have also enabled the webhook for each intent and also put the webhook URL, which is generated from firebase CLI in fulfillment URL section. I am attaching the screenshots of firebase log and JSON response which we see in dialog flow "show JSON" and index.js file as well.I am stuck for 2 weeks to resolve it. </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>'use strict';
  
  process.env.DEBUG = 'actions-on-google:*';
  const { DialogflowApp } = require('actions-on-google');
  const functions = require('firebase-functions');
  let express = require('express');
  let bodyParser = require('body-parser');
  
  // Constants for Dialogflow Agent Actions
  let app = express();
  app.use(bodyParser.urlencoded({ extended: true }));
  app.use(bodyParser.json({type: 'application/json'}));
  
  const BYE_RESPONSE = 'input.search';
  const WELCOME = 'input.welcome';
  
  exports.helloAssistant = functions.https.onRequest((req, res) =&gt; {
    console.log('Request headers: ' + JSON.stringify(req.headers));
    console.log('Request body: ' + JSON.stringify(req.body));
    const asst = new DialogflowApp({request: req, response: res});
  
  
    // Welcome
    function welcome(asst) {
      asst.ask('Want to search product or order history');
      asst.tell('hello Neeraj!');
    }
  
    // Leave conversation with SimpleResponse
  
    function byeResponse (asst) {
      app.post('/',function (req, res) {
        var myProduct = req.body.result.parameters["productParameter"];
        //let intent=asst.getIntent();
        var address ="https://ipadress/rest/v2/electronics/products/search";
        var address1="https://ipadress";
        switch(myProduct){
          case 'BYE_RESPONSE':
            req.post(address);
            break;
  
          case 'WELCOME':
            asst.tell('welcome!');
            break;
  
          default:
            req.post(address1);
            break;
        }
  
        asst.tell('We swear to serve the master of the Precious.');
      });
    }
  
    const actionMap = new Map();
    actionMap.set(WELCOME, welcome);
  
    actionMap.set(BYE_RESPONSE, byeResponse);
    actionMap.set(WELCOME, welcome);
    asst.handleRequest(actionMap);
  });</code></pre>
  </div>
  </div>
  </p>
  
  <p>.<a href="https://i.stack.imgur.com/MLf64.png" rel="nofollow noreferrer">json response in dialogflow</a></p>
  
  <p>.<a href="https://i.stack.imgur.com/fg6Lz.png" rel="nofollow noreferrer">firebase log</a></p>