I've just checked -- most looks from that creator come with a scene only, so if you want to use that "look" in a different or custom scene, you will have to save the look/appearance first. And if you search this thread, there have been multiple instructions on how to save and load a look or appearance. I also agree with
Tomboy Enjoyer -- a lot of those looks use a "CUA" (aka "Custom Unity Asset") as hair, which you need to handle differently (with the CUA Manager plugin), which I personally don't like at all, but it's of course up to you if you want to deal with those additional plugins/settings just to load a look.