How to Increase Upload Speed for GoogleCloudStorage in nodejs

Uploading Files to GCP : Google Cloud Storage In Nodejs

const Storage = require('@google-cloud/storage');
const config = require('./gcloudConfig');
const Multer = require('multer');

const CLOUD_BUCKET = config.get('CLOUD_BUCKET');

const storage = Storage({
  projectId: config.get('GCLOUD_PROJECT')
});
const bucket = storage.bucket(CLOUD_BUCKET);

// Returns the public, anonymously accessable URL to a given Cloud Storage
// object.
// The object's ACL has to be set to public read.
// [START public_url]
function getPublicUrl (filename) {
  return `https://storage.googleapis.com/${CLOUD_BUCKET}/${filename}`;
}

// Express middleware that will automatically pass uploads to Cloud Storage.
// req.file is processed and will have two new properties:
// * ``cloudStorageObject`` the object name in cloud storage.
// * ``cloudStoragePublicUrl`` the public url to the object.
// [START process]
function sendUploadToGCS (req, res, next) {
  if (!req.files) {
    return next();
  }
  const data = req.body;
  if (req.files.length === 0) {
    next();
  }
  data.accountNumber = '';
    for (let index = 0; index < req.files.length; index++) {
      const gcsname = `${data.accountNumber}/${Date.now()}${req.files[index].originalname}`;
      const file = bucket.file(gcsname);
      const stream = file.createWriteStream({
        metadata: {
          contentType: req.files[index].mimetype
        },
        resumable: false
      });
      stream.on('error', (err) => {
        req.files[index].cloudStorageError = err;
        next(err);
      });
    //  console.log(' upload in progress for file ', index);
      stream.on('finish', () => {
        req.files[index].cloudStorageObject = gcsname;
        file.makePublic().then(() => {
          req.files[index].cloudStoragePublicUrl = getPublicUrl(gcsname);
          console.log(' upload completed, public url is ', req.files[index].cloudStoragePublicUrl,
                     ' index ', index, ' total count ', req.files.length);
          if (index === (req.files.length - 1)) {
            next();
          }
        });
      });
      stream.end(req.files[index].buffer);
    }
}
// [END process]

// Multer handles parsing multipart/form-data requests.
// This instance is configured to store images in memory.
// This makes it straightforward to upload to Cloud Storage.
// [START multer]

const multer = Multer({
  storage: Multer.MemoryStorage,
  limits: {
    fileSize: 5 * 1024 * 1024 // no larger than 5mb
  }
});
// [END multer]

module.exports = {
  getPublicUrl,
  sendUploadToGCS,
  multer
};

The issue is the upload speed is very slow, finding a way to upload faster to google cloud storage