Configurable::addAction

public function addAction(\CRestServer $server, int $ownerTypeId, int $ownerId, array $fields, array $layout): ?array
{
	$activity = new ConfigurableRestApp(new ItemIdentifier($ownerTypeId, $ownerId));

	$this->saveActivity($activity, $fields, $layout, $server);
	if (!empty($this->getErrors()))
	{
		return null;
	}

	return [
		'activity' => [
			'id' => $activity->getId(),
		]
	];
}