Peakto saves its catalog structure in a folder that you can define yourself via the Preferences. If you don't do anything special, the default location is : ~/Pictures/
and a folder called Thumbnails where Peakto saves previews and thumbnails.
These files only contain metadata and do not hold any image data. You can share them with us without concerns.
The best is to zip them, and, depending on their size, either send them by email, or using a file transfer service such as Dropbox, Wetransfer.com or iCloud Drive.