I try to call a function which generates a pdf based on row ID from wp table list So i have:

   public function column_default($item, $column_name)
        {
            switch ($column_name) {
              case "ID":
                return $item[$column_name]
              case "pdf":
                    return '
                        <form method="post" action="' . esc_attr('admin-post.php'). '">
                        <input type="hidden" name="id" value="pdf_generate"/>
                        <input type="hidden" name="id" value="' . $item['ID'] . '"/>
                        <input type="submit" name="action" value="PDF"/>
                      </form>';
    }

and I'm trying to call a function in another plugin file :

add_action( 'admin_post_pdf_generate', 'pdf_generator' );
 function pdf_generator()
{
  //something mpdf
}

but each time when I click PDF i see blank page and url is example/wp-admin/admin-post.php without any action