Got PayloadTooLargeError when try to upload file to firebase storage using node js and busboy

I'm trying to upload video file (14 MB) to google firebase storage using firebase cloud functions, Busboy and node js. But I got following error during file upload. This function works with small files without any issue.

PayloadTooLargeError: request entity too large
   at readStream (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\raw-body\index.js:155:17)
   at getRawBody (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\raw-body\index.js:108:12)
   at read (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\body-parser\lib\read.js:77:3)
   at rawParser (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\body-parser\lib\types\raw.js:81:5)
   at Layer.handle [as handle_request] (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\router\layer.js:95:5)
   at trim_prefix (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\router\index.js:317:13)
   at C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\router\index.js:284:7
   at Function.process_params (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\router\index.js:335:12)
   at next (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\router\index.js:275:10)
   at urlencodedParser (C:\Users\User\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\body-parser\lib\types\urlencoded.js:100:7)

These are my code files

index.js

const functions = require("firebase-functions");
const express = require('express');
const FBAuth = require('./util/fbAuth');
const app = express();
const bodyParser = require('body-parser');
const { db } = require("./util/admin");
app.use(express.json({limit: 8 * 1024 * 1024 * 200}));
app.use(express.urlencoded({limit: 8 * 1024 * 1024 * 200}));
const cors = require('cors');

app.use(cors());
app.use(bodyParser.json({limit: 8 * 1024 * 1024 * 200}));
app.use(bodyParser.urlencoded({ limit: 8 * 1024 * 1024 * 200 , extended: true }));

const {
  uploadItem
} = require('./handlers/uploads');

app.post('/upload', FBAuth, uploadItem );

exports.api = functions.https.onRequest(app);

upload.js

const { db, bucket } = require('../util/admin');
const BusBoy = require('busboy');
const path = require('path');
const os = require('os');
const fs = require('fs');
const config = require("../util/config");

exports.uploadItem = (req, res) => {
  console.log('file upload started')
  console.log('data : ' + req.body.name);
  const busboy = BusBoy({headers: req.headers});
  let dataFileName;
  let fileTobeUploaded = {};
  let formData = {};
  busboy.on(
    "field",
    (fieldname, val, fieldnameTruncated, valTruncated, encoding, mimetype) => {
      formData = { ...formData, [fieldname]: val };
    },
  );
  busboy.on('file',(name, file, info) => {
    const { filename, encoding, mimeType } = info;
      //my.image.png
      const fileExtension = filename.split('.')[filename.split('.').length - 1];
      //12345678900.png
      dataFileName = `${Math.round(Math.random()*100000000000)}.${fileExtension}`;
      const filepath = path.join(os.tmpdir(), dataFileName);
      fileTobeUploaded = {filepath, mimeType};
      file.pipe(fs.createWriteStream(filepath)); 
  })
  busboy.on('finish', () => {
    req.body = formData;
      bucket.upload(fileTobeUploaded.filepath, {
          resumable: true,
          metadata:{
              metadata:{
                  contentType:fileTobeUploaded.mimeType
              }
          }
      })
      .then( () => {
        const fileUrl = `https://firebasestorage.googleapis.com/v0/b/${config.storageBucket}/o/${dataFileName}?alt=media`
        const newUpload = {
          uploadItemUrl: fileUrl,
          userHandle: req.user.handle,
          userImage: req.user.imageUrl,
          createdAt: new Date().toISOString(),
          likeCount: 0,
          commentCount: 0
        };
          
        db.collection('uploads').add(newUpload)
      })
      .then( () => {
       
          return res.json({message: "File Uploaded Successfully"});
      })
      .catch(err => {
          console.error(err);
          return res.status(400).json({ error : err.code});
      })
  });
  busboy.end(req.rawBody);
}

Please help me to resolve this. Thank you in advance.