UrlManager::getFileUrl

public function getFileUrl(int $typeId, int $itemId, string $fieldName, int $fileId): Uri
{
	return new ContentUri(BitrixMainEngineUrlManager::getInstance()->create('rpa.item.getfile', [
		'typeId' => $typeId,
		'id' => $itemId,
		'fieldName' => $fieldName,
		'file_id' => $fileId,
	], true)->getUri());
}