ext_localconf.php

<?php
if (!defined ('TYPO3_MODE')) {
	die ('Access denied.');
}

if (!(TYPO3_REQUESTTYPE & TYPO3_REQUESTTYPE_INSTALL)) {
	\TYPO3\CMS\Extbase\Utility\ExtensionUtility::configurePlugin(
		'FluidTYPO3.Fluidcontent',
		'Content',
		array(
			'Content' => 'render',
		),
		array(),
		\TYPO3\CMS\Extbase\Utility\ExtensionUtility::PLUGIN_TYPE_CONTENT_ELEMENT
	);

	\FluidTYPO3\Flux\Core::registerConfigurationProvider('FluidTYPO3\Fluidcontent\Provider\ContentProvider');
	\FluidTYPO3\Flux\Core::registerConfigurationProvider('FluidTYPO3\Fluidcontent\Provider\BackendUserGroupProvider');

	if ('BE' === TYPO3_MODE) {
		$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['cms']['db_new_content_el']['wizardItemsHook']['fluidcontent'] = 'FluidTYPO3\Fluidcontent\Hooks\WizardItemsHookSubscriber';
		$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_userauthgroup.php']['fetchGroups_postProcessing']['fluidcontent'] = 'FluidTYPO3\Fluidcontent\Hooks\GroupAccessListPostProcessor->addAccessLists';
		$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['GLOBAL']['extTablesInclusion-PostProcessing']['fluidcontent'] = 'FluidTYPO3\Fluidcontent\Backend\TableConfigurationPostProcessor';
	}
}

if (!is_array($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['fluidcontent'])) {
	$GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['fluidcontent'] = array(
		'groups' => array('system')
	);
}