Hi Julyt2,
I’m not sure whether the labs will return in their current form. The new viewer on Fab doesn’t have an API yet, so none of the experiments will work with the new viewer.
The Sketchfab labs is a github repository and it’s still available. You can make a fork here from the github account of Sketchfab.
I did so myself and I’m hosting it on github: Sketchfab Labs Experiments. The screenshots experiment is also present.
I can’t guarantee it will all work, but at least the screenshot one has been tested.
If you want to take things further with taking screenshots, take a peek here: https://www.cinefab.io/
Klaas