META description disappear when loading a full HTML page

[Acksop]

When I load a HTML page like this, All my META descriptions disappear.
Does html-pretty-min has a method to keep META and OG safe ?

require_once dirname(dirname(__FILE__)) . DIRECTORY_SEPARATOR . 'vendor/autoload.php';
$app = new \B25\Classe\Application();

ob_start();
$app->launch();
$content = ob_get_clean();

$pm = new Wa72\HtmlPrettymin\PrettyMin();

echo $pm
    ->load($content)
    ->minify()
    ->saveHtml();