Logbook entries can not be downloaded as well as files that cannot be uploaded automatically on logbooks. This falls under the discipline of each user.
The solution for this would be to upload the specific files or logbook information to company documents and download them from there to your computer and upload it manually from an external source if needed.
You will need to make sure the files are up to date.
If you would like to suggest this as product feedback, you can submit this on PeopleHR Ideas Portal via this link:
https://peoplehr.ideas.aha.io/