I have looked into it, however it seems that you have to do a workaround to install this on a RPi, because you need a web browser to authenticate the spotify user.
And I am also not sure if this Add-on will let the Pi work as a Spotify Connect device.
I have a second Pi with Volumio installed, on top of that I installed GitHub - Fornoth/spotify-connect-web
This let the Pi work as a Spotify Connect device, which works like a charm. But I need 2 Pi's: One for audio (Volumio with spotify connect) and one for Video (LE/kodi).
Would be nice if an Add-on makes this work in LE