OBS doesn’t support external cameras directly, but with VDO.Ninja you can connect them to a room and add the scene to your stream.
OBS is a convenient solution for streamers that allows you to create custom scenes for broadcasts. However, you can’t add a camera that isn’t physically connected to the streaming PC.
This problem can be solved using the online service VDO.Ninja. To do this, go to the website and click Create a Room.

You can give the room a name, protect it with a password, set a codec, and configure other parameters. Other people will also be able to join the room later.
For the camera to appear in the room, you or your friends need to join as a participant. In this case, the participant can share video, audio, or their desktop.
In the admin panel, you can arrange the cameras in the desired order, configure the scene settings, and adjust other parameters.

To add the configured scene to OBS, simply copy the CAPTURE A GROUP SCENE link in VDO.Ninja and create a new capture source.