Hi,
I don't understand your message and your request.
HikaShop do not assign a user name if HikaShop does not create a Joomla account during the registration.
So it means that you are using the "guest checkout" and it is fully logical that HikaShop does not create a Joomla account and that the user don't have a login and a password.
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.