public function getKey(): string
    {
        if ($this->key) {
            return $this->key;
        }

        if ($this->config->has('key')) {
            $key = Key::validate($this->config->get('key'), 'group');

            $this->key = $key;

            return $key;
        }

        $this->key = Key::sanitize($this->config->get('title'));

        return $this->key;
    }