The average rider takes around 1-1:30 to ascend the Alpe Du Zwift, one of the hardest climbs on Zwift. However, Zwift offers a badge for those who go under an hour, a whopping 1000 XP if you can do it in under an hour! Pair that with the spinning wheel, and you could earn well over 3000 XP in one run up the Alpe! So just how much power is required in order to tackle this climb in under an hour?
Tests by Zwift Insider, and others like GPlama, Road.cc, and others have found that for the average rider, around 3.2 wpk to go sub one hour.
An interesting tool that uses an algorithm can pretty accurately predict what your Alpe du Zwift time will be if you enter your weight, height, power, and set up. Note that this algorithm does not account for draft, so during peak times, your time could be a decent amount faster than the predicted time.
Here is a link to the site where you can plug all of these details in: https://zwifterbikes.web.app/route/alpe-du-zwift