Selecting App Menu → Properties will allow you to see and change the properties of the currently visible project.
At present there is only an Audio Files tab. This tab shows you all the audio associated with the current project, and whether the audio is embedded or linked externally. The buttons in the tab allow you to:
Note that extracting an embedded file won’t necessarily give you a file containing the audio as it appears in the Audio Pane. In particular, if you have reordered the audio, it is likely to still be in its original order in the extracted file. If you want the audio exactly as it appears in the Audio Pane, use Save Selected Audio.