I can't edit .NEF files in Capture One 22

I imported .NEF files into a session but Capture One 22 won't let me edit them. They are "read only" (eyeball symbol on the photo), and all editing features are grayed out.They are photos I took a few years ago on a Nikon D610. This version of Capture One also has cultural heritage. I read somewhere that maybe this version doesn't support regular RAW photos and only supports digital backs. Is that the issue? Or am I missing something else?