Load css and js assets as absolute paths during twig render

By default, Drupal 8 loads css and js libraries using relative paths.

ie: /core/modules/contextual/css/contextual.module.css

However, because I want to generate static pages to be used by another consumer, how can I have all my libraries as absolute paths instead?

I thought of using the css_alter hook and my code is below:

function rint_css_alter(&$css, \Drupal\Core\Asset\AttachedAssetsInterface $assets) {
    
    foreach ($css as $key => $value) {
        $assetOriginalPath = $css[$key]["data"];
        $css[$key]["data"] =  "https://coaching.ddev.site/$assetOriginalPath";
    }
    print_r($css);
  
}

When I view the print_r result, it seems successful.

Result:

However, when I remove the print_r to view the page, I still see the relative paths for the css assets.

Note: When I used the print_r, I also saw the following error:

The website encountered an unexpected error. Please try again later.<br><em class="placeholder">RuntimeException</em>: Failed to start the session because headers have already been sent

Is there a way to make css and js assets load as absolute paths? as in

http://example.com/core/modules/contextual/css/contextual.module.css