The Camera Raw plugin is only for Photoshop.
Lightroom ships with Camera Raw support built in (Camera Raw code is included in the Lightroom program code). No extra plugin required.
Which Nikon camera are you using?
Supported cameras and version of Lightroom required are listed here:
I was using LR 5 and could not view or edit a Raw file, I was told that I had to have a plugin. I now have LR 6 and before trying to import Raw files from my D5300 I thought I would ask.
Aaa I see, I had to have LR 5.3 acording to that list. Got it...Thanks