Adding react app to an existing wordpress website

You need to include scripts and styles properly as it has been done here https://github.com/radekzz/wordpress-react-in-theme

    add_action( 'wp_enqueue_scripts', 'enqueue_my_react_app' ); 
function enqueue_my_react_app(){ 
    foreach( glob( get_template_directory(). '/myReactApp/build/static/js/*.js' ) as $file ) {      
// $file contains the name and extension of the file        
$filename = substr($file, strrpos($file, "https://wordpress.stackexchange.com/") + 1);         wp_enqueue_script( $filename, get_template_directory_uri().'/myReactApp/build/static/js/'.$filename); 
}   foreach( glob( get_template_directory(). '/myReactApp/build/static/css/*.css' ) as $file ) {        
// $file contains the name and extension of the file        
$filename = substr($file, strrpos($file, "https://wordpress.stackexchange.com/") + 1);         wp_enqueue_style( $filename, get_template_directory_uri().'/myReactApp/build/static/css/'.$filename);   
}
 }