Here's exactly what's about to happen — no surprises. About five minutes.
This signs you in to Wix (or creates a free account if you don't have one), sets up a fresh site, provisions the file-share runtime, and prints your live URL. Re-running it is a no-op — safe to try.
$ npx wix-drop setup --slug yourname
Open the URL — it's your /upload page, just like the demo, but on your own Wix. Drop a file, get a permanent link.