ext_localconf.php

<?php
use TYPO3\CMS\Core\Information\Typo3Version;
use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Core\Imaging\IconRegistry;

defined('TYPO3') || die('Access denied.');

(function () {
    $versionInformation = GeneralUtility::makeInstance(Typo3Version::class);
    // Only include page.tsconfig if TYPO3 version is below 12 so that it is not imported twice.
    if ($versionInformation->getMajorVersion() < 12) {
        ExtensionManagementUtility::addPageTSConfig('
            @import "EXT:youtubevideo/Configuration/page.tsconfig"
        ');
    }

    $iconRegistry = GeneralUtility::makeInstance(IconRegistry::class);
    $iconRegistry->registerIcon(
        'youtubevideo_icon',
        \TYPO3\CMS\Core\Imaging\IconProvider\SvgIconProvider::class,
    ['source' => 'EXT:youtubevideo/Resources/Public/Icons/ext_icon_content.svg']
    );

    $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['tce']['formevals']['Brightside\\Youtubevideo\\Evaluation\\HoursMinutesSeconds'] = '';
})();