ext_localconf.php

<?php
defined('TYPO3_MODE') or die();

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addUserTSConfig('options.saveDocNew.tt_address = 1');

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPItoST43(
    'tt_address',
    'Classes/Controller/LegacyPluginController.php',
    '_pi1',
    'list_type',
    true
);

$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['processDatamapClass'][] = \TYPO3\TtAddress\Hooks\DataHandler\BackwardsCompatibilityNameFormat::class;

// Update scripts
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['ext/install']['update']['tt_address_group'] = \TYPO3\TtAddress\Updates\AddressGroupToSysCategory::class;
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['ext/install']['update']['tt_address_image'] = \TYPO3\TtAddress\Updates\ImageToFileReference::class;
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['ext/install']['update']['tt_address_legacyplugintyposcript'] = \TYPO3\TtAddress\Updates\TypoScriptTemplateLocation::class;

// Register icon
\TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Imaging\IconRegistry::class)->registerIcon(
    'tt-address-plugin',
    \TYPO3\CMS\Core\Imaging\IconProvider\BitmapIconProvider::class,
    ['source' => 'EXT:tt_address/Resources/Public/Icons/ContentElementWizard.gif']
);

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig('
    mod.wizards.newContentElement.wizardItems.plugins {
        elements.tx_ttaddress_pi1 {
            iconIdentifier = tt-address-plugin
            title = LLL:EXT:tt_address/Resources/Private/Language/locallang_pi1.xlf:pi1_title
            description = LLL:EXT:tt_address/Resources/Private/Language/locallang_pi1.xlf:pi1_plus_wiz_description
            tt_content_defValues {
                CType = list
                list_type = tt_address_pi1
            }
        }
        show :=addToList(tx_ttaddress_pi1)
    }
');