How to add react library to existing site?

Question

JavaScript

I am creating a simple site without node.js but with react. I use this tutorial: https://ru.reactjs.org/docs/add-react-to-a-website... For react to work, it is advised to connect it via CDN:

<div id="root"></div>

<!-- Load React. -->
<script src="https://unpkg.com/[email protected]/umd/react.production.min.js" crossorigin></script>
<script src="https://unpkg.com/[email protected]/umd/react-dom.production.min.js" crossorigin></script>

<!-- Load your React component. -->
<script src="root.js"></script>

root.js is written with JSX syntax. Now I want to extend this example from the tutorial and add the react-csv-reader library . But how to do that? If it is imported inside root.js, then there will be an error "SyntaxError: import declarations may only appear at top level of a module". If you try to add it via CDN:

<!-- Load React. -->
<script src="https://unpkg.com/[email protected]/umd/react.production.min.js" crossorigin></script>
<script src="https://unpkg.com/[email protected]/umd/react-dom.production.min.js" crossorigin></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/react-csv-reader.min.js" crossorigin></script>

<!-- Load your React component. -->
<script src="root.js"></script>

then the error "ReferenceError: module is not defined" occurs. How to successfully add this library?