ext_localconf.php

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

// Auto load fluid_styled_content typoscript
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTypoScriptSetup('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/Static/setup.txt">');
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTypoScriptConstants('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/Static/constants.txt">');

// Auto load extension typoscript
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:website/Configuration/TypoScript/pageTSconfig.t3s">');
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTypoScriptSetup('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:website/Configuration/TypoScript/setup.t3s">');
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTypoScriptConstants('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:website/Configuration/TypoScript/constants.t3s">');


$GLOBALS['TYPO3_CONF_VARS']['FE']['pageNotFound_handling'] = 'USER_FUNCTION:' . \Featdd\Website\Hook\PageNotFoundHandler::class . '->handle';