How to make materials downloadable for students
If you have non-purchased items in your Perusall course, such as .pdf files that you uploaded, you can make them downloadable for students. There are two ways to do that: as a default rule, or case-by-case. You CANNOT make purchased texts downloadable.
Step-by-step guide
To make ALL files downloadable (except purchased texts), check the "Allow students to download all uploaded course materials" box in the "Settings" and "Advanced" area of the course. It looks like this:
To make individual files downloadable, check the "allow students to download the file directly" box in the "Library item settings" window. It looks like this: