ext_tables.php

<?php
defined('TYPO3_MODE') or die('Access denied.');

$extPath = \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::extPath('realty');

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPiFlexFormValue(
    'realty_pi1',
    'FILE:EXT:realty/Configuration/FlexForms/Plugin.xml'
);

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPlugin(
    [
        'LLL:EXT:realty/Resources/Private/Language/locallang_db.xlf:tt_content.list_type_pi1',
        'realty_pi1',
        'EXT:realty/Resources/Public/Images/ContentElement.gif',
    ]
);

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
    'realty',
    'Configuration/TypoScript/',
    'Realty Manager'
);

\TYPO3\CMS\Extbase\Utility\ExtensionUtility::registerModule(
    'OliverKlee.Realty',
    'web',
    'openImmo',
    'bottom',
    [
        'OpenImmo' => 'index, import',
    ],
    [
        'access' => 'group',
        'icon' => 'EXT:realty/Resources/Public/Icons/BackEndModule.gif',
        'labels' => 'LLL:EXT:realty/Resources/Private/Language/locallang_mod.xlf',
        // hide the page tree
        'navigationComponentId' => '',
    ]
);

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
    "\n" .  '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:realty/Configuration/TSconfig/ContentElementWizard.txt">' . "\n"
);