Pluto LMS does not have a native file download prevention tool, however, you can use a 3rd Party tool such as Google Drive to prevent files from being downloadable. You can then embed the share code into your course for students to view your files (but not download them).
Use Case Example:
Let's say you have a propriety PDF business guideline that you wish to share with your learners within a course, but you don't want them to download it, to help reduce the risk of sharing information externally, you as the training manager can use this feature to enhances data security and protect proprietary materials while delivering a comprehensive and controlled learning experience within the LMS environment for your users.
UPLOADING YOUR FILE TO GOOGLE DRIVE
Learn how to upload PDFs, Word Docs, etc to Google Drive here: