https://www.techvariable.com/blog/integrating-react-js-into-a-php-application/
„Now can we use React js with Php ?
Yes. This is possible. Reactjs is just the ‘V’ in MVC. React doesn’t care what you are using at backend. One can render React’s components on server side in PHP using V8Js PHP extension, but this is not necessary. Server side rendering in Reactjs is optional. Here are some things you can do:
1. Compile your whole reactjs JSX code using babel. It would be better if you make use of some module bundler like webpack and compile your reactjs code into a single file. Upload that single file on your server.
2. You can populate default states in your react code using php.
The best way to use PHP as backend with React Js as front end is to keep both seperate. Make a stand alone front-end and use PHP to create APIs which interacts with the database. Then consume the API through HTTP AJAX or whatever mechanism React Js contains.„