write a laravel function to find the first h2 tag and insert a html content after this tag

public function insertAfterH2($content)
    {
        $doc = new \DOMDocument();
        libxml_use_internal_errors(true);
        $doc->loadHTML($content);
        $xpath = new \DOMXPath($doc);
        $elements = $xpath->query('//h2');
        if(!is_null($elements)) {
            foreach ($elements as $element) {
                $div = $doc->createElement('div', 'Inserted Text');
                $element->parentNode->insertBefore($div, $element->nextSibling);
            }
        }

        return $doc->saveHTML();
    }