src/Config/Service/ConfigService.php
public function get(string $key)
    {
        $config = $this->repository->findOneBy(['key' => $key]);

        if (!$config) {
            throw new OutOfRangeException('Config "'.$key.'" does not exist.');
        }

        $this->manager->detach($config);

        return $config->getValue();
    }
public function get(string $key)
    {
        $config = $this->repository->findOneBy(['key' => $key]);

        if (!$config) {
            throw new OutOfRangeException('Config "'.$key.'" does not exist.');
        }

        $this->manager->detach($config);

        return $config->getValue();
    }
Get config value

@param string $key
@return mixed
@throws \OutOfRangeException