As far as I know, all that
Blue Iris needs to work with a camera is access to its RTSP stream. If the camera additionally supports ONVIF, it can make adding the camera to BI a lot easier.
Who told you it's not possible to run your camera on Blue Iris?
What is the camera model that you're using?
What does the camera manufacturer suggest to use for recording?
Cameras that were deigned to stream "to the cloud" don't always provide a RTSP stream that allows you to record locally.