Chat::getDialogIdAction

public function getDialogIdAction(string $externalId): ?array
{
	$chatId = Dialog::getChatId($externalId);

	if ($chatId === false || $chatId === 0)
	{
		$this->addError(new ChatError(ChatError::NOT_FOUND));

		return null;
	}

	return ['dialogId' => "chat{$chatId}"];
}