I was assuming the camera worked ... but I was wondering if you had tried to configure Camect to access the camera through the NVR, rather than by using a PoE switch?
WIthout the user name and password it's going to be hard or impossible to access the camera directly. Does the NVR not let you configure those values? (Try the username and password for the NVR if you're not aware of anything else it could be.)
We do have people successfully using other Swann cameras, but this system seems like it may be a bit more difficult than others -- We weren't aware of this, so sorry it was not fully covered in our FAQ. We will update the FAQ to mention it, but I also do still think there's a decent chance it can be made to work.
From what I could find out, the NHD-815 camera is a relabeled Reolink camera (rather than the usual Hikvision relabel) and Swann disabled the web interface on the camera, so you won't be able to set the username/password directly on the camera. At least one person did report that they got the camera to work using the url I mentioned, which is the standard RTSP url for Reolink cameras. However, I guess they knew the correct username and password to use and did not mention where they got the values for them.