For local testing or testing in general, there is no need to send e-mails to real e-mail addresses. Mailtrap service can preview the e-mails for sending.

The inbox page can show credentials (username and password). A list of inboxes is available at Projects page.

import nodemailer from 'nodemailer';
(async () => {
  const emailConfiguration = {
    auth: {
      user: process.env.EMAIL_USERNAME,
      pass: process.env.EMAIL_PASSWORD
    },
    host: process.env.EMAIL_HOST, // 'smtp.mailtrap.io'
    port: process.env.EMAIL_PORT, // 2525
    secure: process.env.EMAIL_SECURE,
  };
  const transport = nodemailer.createTransport(emailConfiguration);
  const info = await transport.sendMail({
    from: '"Sender" <sender@example.com>',
    to: 'recipient1@example.com, recipient2@example.com',
    subject: 'Subject',
    text: 'Text',
    html: '<b>Text</b>'
  });
  console.log('Message sent: %s', info.messageId);
})();

Demo

The demo with the mentioned example is available here.