ext_localconf.php

<?php

declare(strict_types=1);

use TYPO3\CMS\Extbase\Utility\ExtensionUtility;
use TYPO3\CMS\IndexedSearch\Controller\SearchController;
use TYPO3\CMS\IndexedSearch\FileContentParser;
use TYPO3\CMS\IndexedSearch\Hook\DeleteIndexedData;

defined('TYPO3') or die();

// register plugin
ExtensionUtility::configurePlugin(
    'IndexedSearch',
    'Pi2',
    [SearchController::class => ['form', 'search', 'noTypoScript']],
    [SearchController::class => ['form', 'search']],
);

$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearCachePostProc']['indexed_search'] = DeleteIndexedData::class . '->delete';

// Configure default document parsers:
$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['indexed_search']['external_parsers'] = [
    'pdf'  => FileContentParser::class,
    'doc'  => FileContentParser::class,
    'docx' => FileContentParser::class,
    'dotx' => FileContentParser::class,
    'pps'  => FileContentParser::class,
    'ppsx' => FileContentParser::class,
    'ppt'  => FileContentParser::class,
    'pptx' => FileContentParser::class,
    'potx' => FileContentParser::class,
    'xls'  => FileContentParser::class,
    'xlsx' => FileContentParser::class,
    'xltx' => FileContentParser::class,
    'sxc'  => FileContentParser::class,
    'sxi'  => FileContentParser::class,
    'sxw'  => FileContentParser::class,
    'ods'  => FileContentParser::class,
    'odp'  => FileContentParser::class,
    'odt'  => FileContentParser::class,
    'rtf'  => FileContentParser::class,
    'txt'  => FileContentParser::class,
    'html' => FileContentParser::class,
    'htm'  => FileContentParser::class,
    'csv'  => FileContentParser::class,
    'xml'  => FileContentParser::class,
    'jpg'  => FileContentParser::class,
    'jpeg' => FileContentParser::class,
    'tif'  => FileContentParser::class,
];