Hi,
It is possible to create an HikaSerial plugin which would generate a file and attached it to the current order.
The first way does not use HikaShop and his download system.
The serial would be the relative path of the file and thanks to the "onDisplaySerials" trigger, you can display a download link instead of a classical text content.
The second way use HikaShop download system.
At this moment, HikaSerial wouldn't display the serial but it would generate the file and attached it like a unique "hikashop product file".
The customer would be able to download the file, like other "product files" but the downloaded file would be unique.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.