How to deploy a react server-side application with express serve

Maybe you can try this solution extracted from the reactjs official page Example link

const express = require('express');
const path = require('path');
const app = express();

app.use(express.static(path.join(__dirname, 'build')));

app.get('/', function (req, res) {
  res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

app.listen(9000);

In this code the express server app is pointing to the build folder and you just need to route yourself the pages. Indeed, all routes will be quite similar:

...

app.get('/', function (req, res) {
  res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

app.get('/users', function (req, res) {
  res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

app.get('/admin/dashboard', function (req, res) {
  res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

...

As you can see all you need is to deploy the express app and t will do the rest for the react app. For further info, please chech this out: https://create-react-app.dev/docs/deployment/