Get the video playlist link and download from xnxx.com

Under the video you have a selector where you can :

download the video ( low or medium resolution )

copy the master playlist to the clipbord ( normally to be used in a video player )

copy the separate playlists for the separate resolutions to the clipbord ( to be used in a m3u8 downloader )

a browser can not download m3u8 playlists so you need a m3u8 downloader.
There are several but i use "vovsoft m3u8 downloader" , google it it's freeware and works perfect.