What does happen to my data if i drag them into a Babylon Sandbox

Does the data somehow get uploaded to a server.?
We have confidential material here we cant let go outside into the wild.

What the best way to open a .babylon file localy.?

Nope all is local. The only service that we “operate” is the snippet server to save the Playgrounds.
Everything else is local. We do not have (nor want) back end services