When people say "scripted," the showbiz meaning is that they are given like a small booklet (a "script"), and then they repeat the lines that have been written down for them to say.
So no, it's not "scripted" where they are reciting written-down words. Or at least that happens very rarely. (It's partly because it's expensive to hire writers!)
That doesn't mean that everything they say or do is spontaneous... not at all.
The show is some mixture of "actual reality," and devised fiction. And individual scenes that are weirdly in-between, too.