TYPO3 Core

I use TYPO3 8.7.3 and my own extension. So far, I was able to use the

$GLOBALS['TSFE']->config['config']['language']

variable to switch in extbase to another language. This is actually not possible. Is there a new way to switch between languages in the action of a controller? Important for me to create Mails and PDF throw:

\TYPO3\CMS\Extbase\Utility\LocalizationUtility::translate

BR

Daniel