No HDR compatible video encoders available

I have a GTX 3080, and an HDR monitor and am trying to record in HDR at 4k, there doesn't seem to be a lot of information on this since most people still don't use HDR, and also I'm just clueless about video encoders. All I know is that I cannot record in HDR with NVENC H.264 or the software x264 option. I don't know if I need special hardware for this or if this is just software I can download (though from what I've seen, RTX 3080 should support H.265). I tried to install this https://www.free-codecs.com/download/x265_hevc_encoder.htm but I still only have 2 encoder options. I'm not trying to stream or anything, just use the replay buffer feature mostly. What do I need to get this working? Thank you.