Please not that this is for Skype for Windows Desktop (https://www.skype.com/en/download-skype/skype-for-windows/downloading/) and not for the Skype Preview preinstalled with Windows 10. Skype Preview is not supported yet.
Watch this video to see how to enable CatchEye in Skype:
Or, alternatively, here the same instructions in pictures:
And select "CatchEye" as a camera:
If CatchEye is not available in the list of cameras, make sure you have installed Catcheye 3D or CatchEye Lite and restart your computer.