javascript: (function() {
    window.indexedDB.databases().then(function(dbs) {
        dbs.forEach(db => {
            window.indexedDB.deleteDatabase(db.name);
        });
    }).then(function() {
        location.reload();
    });
})();

$GLOBALS['TYPO3_CONF_VARS'] = array_replace_recursive(
    $GLOBALS['TYPO3_CONF_VARS'],
    [
            'SYS' => [
                'caching' => [
                    'cacheConfigurations' => [
                        'pages' => [
                            'backend' => 'TYPO3\\CMS\\Core\\Cache\\Backend\\NullBackend',
                            'frontend' => 'TYPO3\\CMS\\Core\\Cache\\Frontend\\NullFrontend',
                        ],
                        'rootline' => [
                            'backend' => 'TYPO3\\CMS\\Core\\Cache\\Backend\\NullBackend',
                            'frontend' => 'TYPO3\\CMS\\Core\\Cache\\Frontend\\NullFrontend',
                        ],
                        'l10n' => [
                            'backend' => 'TYPO3\\CMS\\Core\\Cache\\Backend\\NullBackend',
                            'frontend' => 'TYPO3\\CMS\\Core\\Cache\\Frontend\\NullFrontend',
                        ],
                    ],
                ],
            ],
        ]
);

// Invalide a Node cache.
\Drupal::service('cache_tags.invalidator')->invalidateTags(['node:5']);
// Invalidate a custom entity cache.
\Drupal::service('cache_tags.invalidator')->invalidateTags(['custom_entity:5']);
// Invalidate a custom cache tag.
\Drupal::service('cache_tags.invalidator')->invalidateTags(['thing:identifier']);