This project was bootstrapped with Create React App.
You can easily add the registration form and login form to your project using the files.
Also note that you should use your database to store and retrieve information, in this project this is done using a PHP script and it is just for testing.
(This method is used in files: Login.js and SignUp.js)
Just download files and run following command in terminal:
npm install
After installing, you can use Login/Register form in your project Wherever you want
<Switch>
<Route path="/login" component={Login} />
<Route path="/signup" component={SignUp} />
<Redirect from="/" to="/signup" />
</Switch>
But don't forget to import react-router-dom and that components
import SignUp from "./components/SignUp";
import Login from "./components/Login";
import { Route, Switch, Redirect } from "react-router-dom";