ayuda.js

const request = require('request');
const fs = require('fs');

const formData = {
  w: 'fileUploader',
  r: 'subir_certif',
  sessionKey: 'jkasdutsvafu76arfs7d5c7v',
  iam : 'nvm2391',
  my_file: fs.createReadStream('/ruta/test.p12'),
};

request.post({url:'https://api-demo.crlibre.org/api.php', formData: formData}, function optionalCallback(err, httpResponse, body) {
  if (err) {
    return console.error('upload failed:', err);
  }
  console.log('Upload successful!  Server responded with:', body);
});