To add wallets for each of coin, go to Admin Panel -> Cryptoniq -> Wallets.
You need to add at least 10-20 addresses or more. Try to add as much as you can. If your shop is big and you have many buy orders, you need to set many addresses. It will help the system to work more properly.
Of course, there can be some problem with setting multiple addresses for 1 coin for one account or one person.
The easiest way to download original program with blockchain and add addresses there. Or you can use some web services which, allow you to do that, e.g.
Note, we're not giving any guarantee for that services. They're are good services, but were provided just as example. Use for your own risk.