Setup to Receive NDI stream with Streamlabs Desktop See this article how to open the firewall for various applications.
If you are encountering issues receiving an NDI stream with Streamlabs Desktop make sure that the application generating the NDI stream is allowed through the firewall and that Streamlabs Desktop receiving the NDI stream is also allowed through the firewall and that both connecting computers are on the private network profile. After installing the SDK, be sure to reboot your computer. To get started with NDI streams and sources you'll need to have the NewTek NDI SDK redist installed on the computer on which you want to use Streamlabs Desktop to receive an NDI stream or on the computer you are using an application to create and send an NDI stream.
For output, see our articles on sending NDI in OBS Studio or Create NDI stream with Scan Converter 2, vMix, or Mobile Device. You will first need to setup your output in order to setup your reception. So you need another application that is capable of capturing and sending out an NDI stream on your local network. Streamlabs Desktop is only able to receive an external NDI stream as a source.