Your project is saved to its own backup directory at a specified interval. So if the program crashes, your unsaved project is not necessarily lost. After you start the program, a dialog appears asking you if you want to restore the project. If you answer yes, the version saved as a backup will be opened.
After opening a project file, you can also select a restore point via File / Restore.

If you want to save the recovered file, choose File / Save As. There you select a suitable location for saving your project. If necessary, also adjust the project name.