Generally, there are two types of Arca-style bracket/plates you use with DSLRs.
![bythom bottom plate](../../_Media/bythom_bottom_plate_med.jpeg)
The first is a plate that simply attaches to the bottom of the camera, typically also allowing access to the battery compartment (above is a plate for the D850). You can find many different plates for most Nikon DSLRs at this site's exclusive advertiser, B&H. I tend to use Kirk or Really Right Stuff plates with my cameras, though I have several other brands and even some generic ones. In general, I recommend that you use a plate designed for your specific camera, as they'll have a bar that helps keep it aligned and not twisting on the bottom of the body (as you can see at the back of the above photo).
![bythom l bracket](../../_Media/bythom_l_bracket_med.jpeg)
The second is called an L-bracket, which allows the camera to be used in both horizontal and vertical orientation (Really Right Stuff bracket shown above). You might notice the cutout on the vertical plate. That's because a good L-bracket allows you to still use the cable connectors on that non-grip side of the camera. Some L-brackets get quite elaborate about this, allowing the vertical portion to be removed, or to be moved further from the camera. This site's exclusive advertiser, B&H, also sells L-brackets for most cameras.
Note that if you use one of the MB-D## vertical grips with your camera, you'll need a different plate or L-bracket for that.
Video shooters will tend to prefer a "cage" to a plate or bracket. See this page for cages.