PricePolicy::getByApp

static function getByApp(array $app): string
{
	if (isset($app['BY_SUBSCRIPTION']) && $app['BY_SUBSCRIPTION'] === 'Y') {
		return PricePolicy::SUBSCRIPTION;
	} else if (isset($app['FREE']) && $app['FREE'] == 'Y') {
		return PricePolicy::FREE;
	}

	return '';
}