Step-1

Install http-proxy-middleware package using npm.

npm i http-proxy-middleware

Step-2

Create a setupProxy.js file in the src directory.

Step-3

Add your proxies to the setupProxy.js file as shown below.

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

module.exports = function (app) {
    app.use(
        ["/api/users/login", "/api/users/register"],
        createProxyMiddleware({
            target: "http://localhost:5000",
        })
    );
};

NOTE: You don't need to import this file anywhere. It is automatically registered when you start the development server. Also, anytime you make a change to the setupProxy.js file, you’ll need to restart your server.

For more information, check out the following resourse:

https://create-react-app.dev/docs/proxying-api-requests-in-development/