You never specified if you have an HDR-capable monitor. You can’t use HDR without that. Then you have to ensure that your monitor is connected via either the HDMI or DP port that supports HDR. DIfferent monitors will have different standards on their ports. Ditto for video cards. And of course, you need a cable that’s able to carry the signal. Not all HDMI and DP cables are equal. There are different versions of these protocols that require cables capable of carrying that signal.
Once you have all that, you have to make sure it’s enabled in your monitor’s onboard menus, then enable it in Windows via the display settings. At that point, it will be available to be enabled in the sim.