So that it snows in certain places or something? I play on Nintendo Switch.
It works on the Java, I think it is in a Snowy Taiga-Bion. Unfortunately, I don't know whether that's the same on the switch, but I think so
No it can't.
The whole superflat world is (unless you changed it when you created the world) a plains biome and it doesn't snow in them.
Yes but the world already exists
(I'm playing)
I'm not sure, but I think a Flatworld consists of only one biome, so no
Either when creating the world setting or mark 2 points with WorldEdit and with // setbiome you can change the biome into a snow biome.