use TYPO3\CMS\Core\Utility\GeneralUtility; // Create a new directory named 'my_new_directory' inside the TYPO3 document root $path = GeneralUtility::getFileAbsFileName('my_new_directory'); GeneralUtility::mkdir($path);In this example, we use GeneralUtility to get the absolute file path of the new directory we want to create ('my_new_directory') using the getFileAbsFileName function. We then use mkdir to create the directory. The package library for this function is TYPO3\CMS\Core\Utility\GeneralUtility.