I’m a fairly new Zwifter. On the screen where you save the ride, I’m not seeing the Everest challenge. The only one there is Ride California. I assume it becomes available when you finish this?
Click on the California Challenge. At the bottom of the picture, you’ll see the option to “select a different challenge”. Click on that and you will see the option to switch to Everest.
Oh right, thanks for the info. This UI could sure do with some improvements.