FrontendConfigurationManager

Extern: Config überall aufrufen

$cManager = $this->objectManager->get('TYPO3\CMS\Extbase\Configuration\FrontendConfigurationManager');
$extensionConfig = $cManager->getConfiguration($extensionName, NULL);

Intern: In der Extension aufrufen

$config = $this->configurationManager->getConfiguration(ConfigurationManagerInterface::CONFIGURATION_TYPE_FRAMEWORK);