Going through the App channels on the Xbox One S, while some popular streaming services like Amazon and Hulu are available, Netflix is nowhere to be seen.
Unless Microsoft decides to support Netflix, in the meantime you can use the Roku 4 or Chromecast Ultra either directly connected to the TV or through the Xbox One S's HDMI IN port. Note however, the Xbox One S doesn't seem to pass on any 4K HDR content from its HDMI IN port.