Did you install the NewTek SDK files too on both client and server? If I remember, just download the full MSI installer and you will get the SDK as part of the distribution.
Set it up like this...
Gaming PC (you may have one or more)
- NDI Plugin and Newtek NDI API installed
- OBS Studio installed
NDI Output Settings Dialog Box
- Main output checkbox checked
- Main Output name - Joes Gaming PC (or whatever you want, but must be unique name on network)
- Preview Output unchecked
Dedicated NDI Streaming Server
- NDI Plugin and Newtek NDI API installed
- OBS Studio installed
NDI Output Settings Dialog Box
- Main output checkbox checked
- Main Output name - OBS Stream (or whatever you want)
- Preview Output unchecked
NDI Source (at least one NDI source, correlated to all the gaming PCs to capture)
- Source name: Joes PC
- Bandwidth: Highest
- Sync: Network
- YUV Range: Full
- YUV Color Space: BT.709
- Latency Mode: Normal (safe)