如何解决Firebase函数中的“无效的登录用户名和密码不被接受”错误？

Question

我正在尝试向用户注册该应用程序时向他们发送欢迎电子邮件。

const transporter = nodemailer.createTransport({
  service : 'gmail',
  auth: {
      user: '',
      pass: ''
  }
});

exports.sendWelcomeEmail = functions.auth.user().onCreate((user) => {
    const email = user.email; // The email of the user.
    const displayName = user.displayName; // The display name of the user.

    return sendWelcomeEmail(email, displayName);
  });
async function sendWelcomeEmail(email, displayName) {
  const mailOptions = {
    from: `${APP_NAME} <my email>`,
    to: email,
  };

  mailOptions.subject = 'Welcome to ${APP_NAME}!';
  mailOptions.text = `Hey ${displayName || ''}! Welcome to ${APP_NAME}. I hope you feel better after using our app`;
  await transporter.sendMail(mailOptions);
  console.log('New Welcome email sent to:', email);
  return null;
}

但是我收到一条错误消息，提示“无效的登录用户名和密码不被接受”。我也试着做 那也不行。