I suspect the question is whether you installed ALL of the correct NDI related software... both NDI Tools (usually) and then NDI plugin for OBS. The typical recommendation is to use the free NDI Tools from newtek, and make sure (before even starting OBS) that NDI video feed is working on PC. Then reading first, doing some research/testing, then asking in the plugin thread usually best way to get assistance. Don't ignore the pinned post in this forum on posting OBS log from a recording or streaming session