Removing the header menu from whmcs

Hello,

I want to remove the header menu from the WHMCS site. However, I have reached the codes in the WHMCS Bridge plugin, but I have not been able to remove the header menu. Can you please help me with what I did or didn’t do? I found a code, but whatever I delete, my site doesn’t open the site.

    if (!is_main_query()) return $content;

    $cf = get_post_custom($post->ID);

    if (isset($_REQUEST['ccce']) || (isset($cf['cc_whmcs_bridge_page']) && $cf['cc_whmcs_bridge_page'][0]==WHMCS_BRIDGE_PAGE)) {
        if (!isset($cc_whmcs_bridge_content)) { //support Gantry framework
            $cc_whmcs_bridge_content = cc_whmcs_bridge_parser();
        }
        if ($cc_whmcs_bridge_content) {
            $content='';
            ob_start();

            if (!function_exists('dynamic_sidebar') || !dynamic_sidebar('whmcs-top-page')):
            endif;

            $content .= ob_get_clean();
            $content .= '<div id="bridge">';

            if (is_array($cc_whmcs_bridge_content) && isset($cc_whmcs_bridge_content['main']))
                $content .= $cc_whmcs_bridge_content['main'];

            $content .= '</div><!--end bridge-->';

            ob_start();

            if (!function_exists('dynamic_sidebar') || !dynamic_sidebar('whmcs-bottom-page')):
            endif;

            $content .= ob_get_clean();

            if (get_option('cc_whmcs_bridge_footer')=='Page')
                $content .= cc_whmcs_bridge_footer(true);