Hi,
HikaMarket have his own configuration panel.
When you are in HikaShop in the backend, you can see a menu named "HikaMarket" (just between "Display" and "Documentation").
In this menu you will find the HikaMarket pages (the configuration, the vendors, etc).
After that, when you edit a product in HikaShop, you will have a vendor selector (below "published").
It will open a popup to select a vendor. You first need to have a vendor to select so you have to be sure that you already create a vendor (in HikaMarket > Vendors).
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.