Once complete, Enscape will automatically extract the files. You will see a confirmation message: "Offline Asset Library ready for use." Navigate to your destination folder. You should see a series of .dat files and subfolders containing thumbnails and geometry.
For official technical documentation on this feature, refer to the Chaos Support Portal Enscape Knowledge Base Are you experiencing a specific error code folder permission issue while trying to save the assets? Downloading Enscape Cosmos Assets for Offline Use - Chaos download enscape asset library offline