Nikon z6ii

It should be supported:

Digital camera RAW formats supported by iOS 14, iPadOS 14, and macOS Big Sur - Apple Support

Sometimes it helps to put the Raw File into Photos and just leave it open for a while. I think Apple only downloads RAW support when needed.

Do you mean you cannot see the images on the camera on the computer? With my Nikon, the SD card is in a proprietary format and neither the camera nor the card in the card slot will appear in the Finder.

That requires a translator to overcome and the are two free options, and you already have one of your Mcc.

The easy way—and the one that comes with macOS—is Image Capture.

Transfer images in Image Capture on Mac - Apple Support

When I plug my Nikon into the iMac, Image Capture—not the Finder—shows the camera (or its card) in the sidebar:

You can import images directly from the app to Photos or to a folder you designate.

The second option is Nikon's image management software, available at no cost on their support site. My older DSLR uses ViewNX-i— a newer camera may have a different app. The downside is that there is a steep learning curve.