protected function deleteHtml($key): void
    {
        $paths = [];
        $paths[] = MaskUtility::getTemplatePath($this->extSettings, $key);
        $paths[] = MaskUtility::getTemplatePath($this->extSettings, $key, false, $this->extSettings['backend']);
        foreach ($paths as $path) {
            if (file_exists($path)) {
                unlink($path);
            }
        }
    }