criado PDF usando Html2pdf eu não sei como salvar e recuperar pdf

<?php
    $content = "
<page>
    <h1>Exemple d'utilisation</h1>
    <br>
    Ceci est un <b>exemple d'utilisation</b>
    de <a href='http://html2pdf.fr/'>HTML2PDF</a>.<br>
</page>";

    require_once(dirname(__FILE__).'/html2pdf/html2pdf.class.php');
    $html2pdf = new HTML2PDF('P','A4','fr');
    $html2pdf->WriteHTML($content); // in $content you put your content to have in pdf
    $html2pdf->Output('exemple.pdf');
?>

  $html2pdf->Output('directory/filename_xxxx.pdf', 'F');
  Add the name to mysqldb.