How to add async or defer in all js file included in wordpress website

<!--?php function rj_script_tag_defer($tag, $handle) {    if (is_admin()){        return $tag;    }    if (strpos($tag, '/wp-includes/js/jquery/jquery')) {        return $tag;    }    else if($handle=='jquery' )  // if you want to ignore any js use this condition    {                 return $tag;    }    if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE 9.') !==false) {    return $tag;    }    else {        return str_replace(' src',' async="async" src', $tag);    }}add_filter('script_loader_tag', 'rj_script_tag_defer',10,2);?-->