Google Cloud Function for Facebook Webhook

function.js

const config = require('./config.json');
const bigquery = require('@google-cloud/bigquery')();

function insertRows(rows) {
  bigquery
    .dataset(config.DATASET)
    .table(config.TABLE)
    .insert(rows)
    .then((data) => {
      console.log(`${rows.length} rows inserted.`);
      console.log(data[0]);
    })
    .catch((err) => {
      console.error(`ERROR: ${err}`);
    });
}

function processData(req, res) {
  // See the structure of JSON payloads here: 
  // https://developers.facebook.com/docs/graph-api/webhooks#callback
  let n_entries = 0;
  let n_changes = 0;
  let changes = [];
  req.body.entry.forEach((e) => {
    n_entries++;
    e.changes.forEach((c) => {
      n_changes++;
      let value = c.value;
      value.id = e.id;
      changes.push(value);
    });
  });
  res.status(200).send();

  insertRows(changes);
  console.log(changes);
  console.log(`${n_entries} entries, ${n_changes} changes`);
}

exports.webhook = function webhook(req, res) {
  switch (req.method) {
    case 'GET':
      // Handle verification requests
      if (req.query['hub.mode'] === 'subscribe' &&
        req.query['hub.verify_token'] === config.VERIFY_TOKEN) {
        res.status(200).send(req.query['hub.challenge']);
      } else {
        res.sendStatus(403);
      }
      break;
    case 'POST':
      // Notifications are sent using POST requests
      processData(req, res);
      break;
    default:
      res.status(500).send({ error: `Request method error: ${req.method}`});
      break;
  }
};

Thaks you this help me !