Here is the rtsp string to put in the zoneminder monitor config:
rtsp://admin:admin@IP ADDRESS OF CAMERA:554/stream2
Here is the procedure that was used to find this information. It may work for other Jennov cameras.
1) The camera came with a software package to view the stream. Install this on a Windows Machine or VM.
2) Start Wireshark and filter for rstp (There are YouTube videos that you can watch to help with this.)
3) Once filtered, right click and then select Follow --> TCP Stream
4) Search for the rtsp:// string.