cms-fluid-styled-content/Configuration/TCA/Overrides/sys_template.php

<?php

defined('TYPO3') or die();

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
    'fluid_styled_content',
    'Configuration/TypoScript/',
    'Fluid Content Elements'
);
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
    'fluid_styled_content',
    'Configuration/TypoScript/Styling/',
    'Fluid Content Elements CSS (optional)'
);