How to redirect port for React production – Plesk

I am trying to setup both Express.js and React.js apps on the same Ubuntu server. This is a VPS which runs Plesk Onyx where we have a lot of virtual hosts that run over port 80.

To run them continuosly I have installed and ran forever, then these apps starts on ports 3000and 5000 (for instance).

I executed commands:

forever start -c "node src/server" ./ -l ./express.log
forever start -c "npm start" ./ -l ./react.log

Neither of the log files saves nothing, but that is not the point. Both are running as in the previous commands line but in those ports.

How do I redirect at least React port to 80 for this only app? Usually with PHP should work .htaccess but I am not sure for Nodejs.

Edit: The form code which sends from the React app through Express (worked great with React.js before building with npm run build:

The React component:

sendEmail(evt) {
    evt.preventDefault();
    (async () => {
        let response = await fetch(
            `${window.location.origin}/contacto`,
            options
        );
        let data = await response.json();

        if (!data.success) {
            this.setState(
                Object.assign(this.state, {
                    error: true,
                    texto: { error: <p>{data.message}</p> },
                    alert: {
                        visible: true,
                        tipo: "alert-danger"
                    }
                })
            );
        } else {
            this.setState(
                Object.assign(this.state, {
                    error: false,
                    texto: { error: <p>{data.message}</p> },
                    alert: {
                        visible: true,
                        tipo: "alert-success"
                    }
                })
            );
            document.getElementById("formulario-contacto").reset();
        }
    })();
}

The Express stuff:

// Static site init
server.use("/", express.static("build"));

server.post("/contacto", (req, res) => {
  try {
    server.mailer.send(
      "email",
      {
        to: process.env.EMAIL_FROM,
        subject: `Contacto ${req.body.asunto}`,
        body: req.body
      },
      err => {
        if (err) {
          res.send({ success: false, message: err });
        } else {
          res.send({ success: true, message: "Mensaje enviado" });
        }
      }
    );
  } catch (err) {
    res.send({ success: false, message: err });
  }
});