Keynote outlines disappeared on iPad

Hello, I created several outlines in the Keynote app on my iPad. However, recently my iPad has had really low storage, and since then, all the Keynote outlines have disappeared. I’ve searched for them through the Keynote app and the Files app. I can’t remember whether they were saved to the device or iCloud Drive, but they’re nowhere to be found. Is there any way to find them or are they lost forever?