Hi,
HikaShop do not really have that feature ; it requires a subscription component in order to make it fully work.
In our documentation, under "integration" you will be able to see two subscription component compatible with HikaShop : Emerald and Akeeba Subs.
www.hikashop.com/support/documentation.html
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.