BFile::download

public function download($fileId, $fileName = '')
{
	if(intval($fileId) > 0)
	{
		$fileDescription = CFile::GetFileArray($fileId);
		$options = [];
		if($fileName)
		{
			$options['attachment_name'] = $this->correctFileName($fileName);
		}
		CFile::ViewByUser($fileDescription, $options);
		return true;
	}

	return false;
}