app.js

const dialogflow = require('dialogflow');
const uuid = require('uuid');
const express=require('express');
const bodyparser=require('body-parser');
const app=express();
const port=3000;
 // A unique identifier for the given session
 const sessionId = uuid.v4();

app.use(bodyparser.urlencoded({
  extended:false
}))

app.use(function(req, res, next){
  res.setHeader('Access-Control-Allow-Origin','*');
  res.setHeader('Access-Control-Allow-Methods','GET, POST,OPTIONS ,PUT, PATCH, DELETE');
  res.setHeader('Access-Control-Allow-Headers','X-Requested-with,content-type');
  res.setHeader('Access-Control-Allow-Credentials',true);
  next();
});

app.post('/send-msg',(req,res)=>{
  runSample(req.body.MSG).then(data=>{
    res.send({Reply:data})

  })
})

/**
 * Send a query to the dialogflow agent, and return the query result.
 * @param {string} projectId The project to be used
 */
async function runSample(msg,projectId = 'pizzabot-wvesmr') {
 

  // Create a new session
  const sessionClient = new dialogflow.SessionsClient({
    keyFilename:"C:/chatbot/Pizzabot-0b91cc3e7f33.json"
  });
  const sessionPath = sessionClient.sessionPath(projectId, sessionId);

  // The text query request
  const request = {
    session: sessionPath,
    queryInput: {
      text: {
        // The query to send to the dialogflow agent
        text: msg,
        // The language used by the client (en-US)
        languageCode: 'en-US',
      },
    },
  };

  // Send request and log result
  const responses = await sessionClient.detectIntent(request);
  console.log('Detected intent');
  const result = responses[0].queryResult;
  console.log(`  Query: ${result.queryText}`);
  console.log(`  Response: ${result.fulfillmentText}`);
  if (result.intent) {
    console.log(`  Intent: ${result.intent.displayName}`);
  } else {
    console.log(`  No intent matched.`);
  }
  return result.fulfillmentText
}

app.listen(port,()=>{
  console.log("running on port")
})