function restrict_advent24_download_access() { if (is_page('advent24-download') && (!isset($_SERVER['HTTP_REFERER']) || strpos($_SERVER['HTTP_REFERER'], 'cedarfund.org/advent2024') === false)) { wp_redirect('https://www.cedarfund.org/advent2024'); exit; } } add_action('template_redirect', 'restrict_advent24_download_access');