Ok, just a note to everyone ! It is online service and your diagrams are stored in the "cloud" and you have zero control over it. Please, do not post your company's secret in form of diagrams. Recently, we caught one of the contractors using Draw.io to make diagrams of brand new systems that we are designing(we are fortune 40 company). System is expensive, very sensitive.
And where did the user store the data?
Addtionally, you can deploy a local version via docker, or use the stand-alone desktop version, https://github.com/jgraph/drawio has the links.