public function prepare(string $method, array $parameters)
    {
        // Delete any empty key
        $parameters = $this->deleteEmptyKeys($parameters);

        // Add the API Key
        $parameters['apiKey'] = $this->flow->getCredentials()->apiKey;

        // Sort the parameters
        ksort($parameters);

        // Return the final data
        switch ($method) {
            case 'get':
                return $this->prepareGet($parameters);
            case 'post':
                return $this->preparePost($parameters);
            default:
                return null;
        }
    }