useProxy.js not working - new code provided

[svdoever]

Please use the following code:

const { createProxyMiddleware } = require('http-proxy-middleware');

module.exports = function(app) {
  app.use(createProxyMiddleware('/.netlify/functions/', {
    target: 'http://localhost:9000/',
    "pathRewrite": {
      "^/\\.netlify/functions": ""
    }
  }));
};