The cam that is powered by a power supply and is Wi-Fi? You would need to be able to perform at least these 2 things:
- How to set its wireless IP to a unique, static IP in the same subnet as the NVR's LAN and add it to the NVR that way.
- Add it to the NVR using "private protocol" as found on page 10 of the PDF file here.
If the cam is ONVIF compliant, you should be able to run the free
ODM (ONVIF Device Manager), log into the cam's IP, select "Live Video" and see the URL you'll need for that "private protocol" at the bottom right of the screen.
That's really the best I can suggest, I know of no other way since there's a lot unknowns and I'm not familiar with any of your devices.