Hi,
You can create an HikaShop product which will be visible and free for users of a specific group.
(Note: The price per user group requires HikaShop Business)
If a product is free, you do not need to pay anything.
The shipping step and the payment step won't be displayed if the order is free and does not have any weight.
When the free order will be made, HikaSerial will generate the serial code (the voucher) and the plugin attach serial will send the voucher image in the order confirmation email.
You will keep a trace in your website that the user got the voucher and could track it if required.
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.