how to collect multiple fields using busboy nodejs
app.post('/somewhere', (req, res) => {
  let formData = new Map();
  req.busboy.on('field', function(fieldname, val) {
    formData.set(fieldname, val);
  });
  req.busboy.on("finish", function() {
    console.log(formData) // Map { 'name' => 'hi', 'number' => '4' }
    // here you can do 
    formData.get('name') //  'hi'
    formData.get('number') //  '4'
    // any other logic with formData here
    res.end()
  });
});