React / Express api Необработанный отказ (TypeError)

Question

Я реализую функцию сброса пароля в своем приложении на основе этого учебника: https://itnext.io/password-reset-emails-in-your-react-app-made-easy-with-nodemailer-bb27968310d7?gi=574338d418a9

В форме сброса пароля при отправке электронного письма я получаю письмо для сброса пароля с express и может сбросить пароль с помощью токена:

Executing (default): SELECT "id", "username", "email", "usertype", "password_digest", "avatar", "reset_password_token" AS "resetPasswordToken", "reset_password_expires" AS "resetPasswordExpires", "created_at" AS "createdAt", "updated_at" AS "updatedAt" FROM "users" AS "user" WHERE "user"."email" = 'me@gmail.com';
Executing (default): UPDATE "users" SET "reset_password_token"=$1,"reset_password_expires"=$2,"updated_at"=$3 WHERE "id" = $4
Message sent: undefined f68a6a6d5e8892f9b0b24ef13ebeda4e2b2b40ff

Однако после отправки пароля вышеприведенное сообщение сервера зависает до тех пор, пока я не остановлюсь express, и в этот момент мне представляется это ошибка в React.

Unhandled Rejection (TypeError): Cannot read property 'data' of undefined
ForgotPassword.sendEmail
src/editModules/View/ForgotPassword.jsx:58

ForgotPassword.jsx (React)

class ForgotPassword extends Component {
  constructor(props) {
    super(props);

    this.state = {
      email: "",
      showError: false,
      messageFromServer: "",
      showNullError: false
    };
  }

  handleChange = name => event => {
    this.setState({
      [name]: event.target.value
    });
  };

  sendEmail = async e => {
    e.preventDefault();
    const { email } = this.state;
    if (email === "") {
      this.setState({
        showError: false,
        messageFromServer: "",
        showNullError: true
      });
    } else {
      try {
        const response = await axios.post(
          "http://localhost:4000/forgot/",
          {
          email,
        });
        console.log(response.data);
        if (response.data === "recovery email sent") {
          this.setState({
            showError: false,
            messageFromServer: "recovery email sent",
            showNullError: false
          });
          // this.props.history.push("/checkmail");
        }
    } catch (error) {
        console.error(error.response.data);
        if (error.response.data === "email not in db") {
          this.setState({
            showError: true,
            messageFromServer: "",
            showNullError: false
          });
        }
      }
    }
  };

  render() {
    const { email, messageFromServer, showNullError, showError } = this.state;

    return (
      <>
        <Header />
        <div id="page-container">
          <div id="auth-container">
              <h1 className="center-it">Forgot Password</h1>
              <form onSubmit={this.sendEmail}>
                <input
                  className="input"
                  id="email"
                  label="email"
                  style={{width: '100%'}}
                  value={email}
                  onChange={this.handleChange("email")}
                  placeholder="Email Address"
                />
                <br />
                <br />
                <button className="auth-button">
                  Send Password Reset Email
                </button>
              </form>
              {showNullError && (
                <div>
                  <p id="alert">The email address field is empty.</p>
                </div>
              )}
              {showError && (
                <div>
                  <p id="alert">
                    That email address isn&apos;t recognized. Please try again
                    or register for a new account.
                  </p>
                </div>
              )}
              {messageFromServer === "recovery email sent" && (
                <div>
                  <p id="alert">Password Reset Email Successfully Sent!</p>
                </div>
              )}
            </div>
          </div>
        <Footer />
      </>
    );
  }
}

export default withRouter(ForgotPassword);

ForgotPassword. js (Express)

pwRouter.post('/forgot', async (req, res) => {
  if (req.body.email === '') {
    res.status(400).send('email required');
  }
  console.error(req.body.email);
  User.findOne({
    where: {
      email: req.body.email,
    },
  }).then((user) => {
    if (user === null) {
      console.error('email not in database');
      res.status(403).send('email not in db');
    } else {
      const token = crypto.randomBytes(20).toString('hex');
      user.update({
        resetPasswordToken: token,
        resetPasswordExpires: Date.now() + 360000,
      });

      const options = {
        auth: {
          api_user: process.env.UN,
          api_key: process.env.PW
        }
      };

      const client = nodemailer.createTransport(sgTransport(options));

      const email = {
        from: 'support@gmail.com',
        to: `${user.email}`,
        subject: 'Password Reset Link',
        text:
          'You are receiving this because you (or someone else) have requested the reset of the password for your account.\n\n'
          + 'Please click on the following link, or paste this into your browser to complete the process within one hour of receiving it:\n\n'
          + `http://localhost:3000/reset/${token}\n\n`
          + 'If you did not request this, please ignore this email and your password will remain unchanged.\n',
      };

      client.sendMail(email, function(err, info){
        if (err ){
          console.log(err);
        }
        else {
          console.log('Message sent: ' + info.response, token);
        }
    });
    }
  });
});

module.exports = {
  pwRouter,
};

I'm застрял на этом этапе, так как все другие функции аутентификации в приложении работают правильно. Я прошел репо, это основано на том, что я не могу точно понять, где я ошибся.