How to use CDN within kirby 3?

Kirby 3
8

Thanks. Now my assets (css and js) path has changed.
But the path of the media has not changed.
site/plugins/cdn/index.php

<?php
Kirby::plugin('getkirby/cdn', [
    'components' => [
        'url' => function ($kirby, $path, $options, $original) {
            if (preg_match('!assets!', $path)) {
                if (option('cdn', false) !== false) {
                    return option('cdn.domain') . '/' . $path;
                } else {
                    return $original($path, $options);
                }
            } else {
                return $original($path, $options);
            }
        }
    ]
]);

site/config/config.php

<?php

return [
    'cdn' => [
       'domain' => 'http://files.emptyarea.com'
    ],
    'debug' => true,
];