In that example below we are going to send the IP stream of an Avonic CM70-IP camera to OBS, use the "Virtual camera" feature from OBS which will allow to have that camera in the video options of any videoconferencing software (Zoom, Skype, Teams etc) as if it was a simple USB camera!
Start by opening OBS and creating a new scene (here we will call it "VideoConferencing"). Then, add a new source by clicking the + icon (Sources column) and select "Media Source" option
Rename it if you wish ("VideoConf Camera" in that example):
Disable Local File option and fill the Input field (here with "rtsp://192.168.5.163/live/av0" which is the default local IP stream of an CM70-IP camera)
The video stream should appear in the OBS windows. Then click on the "Start Virtual Camera" button on the right:
Now you camera (stream) is ready to be available in the cameras list of the videoconferencing platforms: