Load Custom Assets In Joomla! Core mod_custom using this layout override

customasset.php

<?php
declare(strict_types=1);

/**
 * Custom Assets
 *
 * @version       1.0.0
 * @package       Customasset
 * @author        Alexandre ELISÉ <contact@alexapi.cloud>
 * @copyright (c) 2009-2022 . Alexandre ELISÉ . Tous droits réservés.
 * @license       GPL-2.0-and-later GNU General Public License v2.0 or later
 * @link          https://alexapi.cloud
 */

use Joomla\CMS\Factory;
use Joomla\CMS\HTML\HTMLHelper;
use Joomla\CMS\Uri\Uri;

defined('_JEXEC') or die;

$app = Factory::getApplication();

/**
 * @var \Joomla\CMS\Document\HtmlDocument $document
 */
$document = $app->getDocument();

$appIconsCustomPath = Uri::root() . 'images/touch';

$customHeadTags = <<<CUSTOMHEAD
<link rel="apple-touch-icon" sizes="180x180" href="$appIconsCustomPath/apple-touch-icon.png"><link rel="icon" type="image/png" sizes="32x32" href="$appIconsCustomPath/favicon-32x32.png"><link rel="icon" type="image/png" sizes="192x192" href="$appIconsCustomPath/android-chrome-192x192.png"><link rel="icon" type="image/png" sizes="16x16" href="$appIconsCustomPath/favicon-16x16.png"><link rel="manifest" href="/manifest.json"><link rel="mask-icon" href="$appIconsCustomPath/safari-pinned-tab.svg" color="#019aff"><meta name="msapplication-TileColor" content="#ffc40d"><meta name="msapplication-TileImage" content="$appIconsCustomPath/mstile-144x144.png"><meta name="theme-color" content="#ffffff">
CUSTOMHEAD;

$document->addCustomTag($customHeadTags);

HTMLHelper::_('script', 'https://cdnjs.cloudflare.com/ajax/libs/tarteaucitronjs/1.9.5/tarteaucitron.min.js',
	[],
	[
		'integrity' => 'sha512-81BpselCKwXBQl7OCqIShbHVaqBx3g6qyPieqC7IPsCzWwAXlwLUKUnAMRvtii3RLp1ZoqLmtg4VLeGm2mUNfw==',
		'crossorigin' => 'anonymous',
		'referrerpolicy' => 'no-referrer',
	]);

$cookieConsentScript = <<<COOKIECONSENTSCRIPT
tarteaucitron.init({
"privacyUrl": "https://example.com/privacy",
"readmoreLink": "https://example.com/readmore",
"hashtag": "#cookies",
"cookieName": "tarteaucitron",
"orientation": "bottom",
"showAlertSmall": true,
"cookieslist": true,
"showIcon": false,
"iconPosition": "BottomLeft",
"adblocker": false,
"DenyAllCta" : true,
"AcceptAllCta" : true,
"highPrivacy": true,
"handleBrowserDNTRequest": false,
"removeCredit": true,
"moreInfoLink": true,
"useExternalCss": false,
"useExternalJs": false,
"mandatory": true
});
COOKIECONSENTSCRIPT;

$document->addScriptDeclaration($cookieConsentScript);

$cookieConsentServiceScript = <<<COOKIECONSENTSERVICESCRIPT
(function (tarteaucitron) {
tarteaucitron.user.gtagUa = 'UA-XXXXXXXX-X';
(tarteaucitron.job = tarteaucitron.job || []).push('gtag');
(tarteaucitron.job = tarteaucitron.job || []).push('facebook');
(tarteaucitron.job = tarteaucitron.job || []).push('twitter');
(tarteaucitron.job = tarteaucitron.job || []).push('pinterest');
(tarteaucitron.job = tarteaucitron.job || []).push('youtube');
(tarteaucitron.job = tarteaucitron.job || []).push('vimeo');
(tarteaucitron.job = tarteaucitron.job || []).push('googlemapssearch');
}(window.tarteaucitron));
COOKIECONSENTSERVICESCRIPT;

$currentBody = $app->getBody();
$modifiedBody = str_replace('</body>', sprintf('%s%s',$cookieConsentServiceScript, '</body>'), $currentBody);
$app->setBody($modifiedBody);