Indoor track & Strava segments

Anyone knows how the indoor track works? No GPS sure, it is indoor, but I wonder if it is a better sport mode to use for Elliptical machines. With F3 I used to us Treadmill, just to record some distance and pace, which both were shorter and slower than the real but at least it gave me some... What do you guys use for Elliptical machines? I am aware there is an app, but it does not record the distance in GC.

Strava segments - am I right to presume I need Strava premium to make this work?

All the best,
Meste