When you select "Download PDF" at the upper right corner, a new tab with your material should appear in the browser. Here you can download it to your PC.
If this does not happen, it may be because:

You are accessing the platform via another browser than Google Chrome or Firefox. These two browsers are the ones that are best developed for newer software systems such as Candeno. Therefore, you can experience technical challenges if you use older browser versions such as Safari or Edge. We therefore recommend that you download Google Chrome or Firefox. 

In case you are already accessing Candeno via Google Chrome or Firefox, but is still not able to download as PDF, it may be because your browser had blocked pop-ups. When pop-up windows are blocked, the address bar is marked with ‘Pop-up windows blocked’, and you must then allow these by clicking on the icon. 

A guide to allow pop-ups in Chrome can be found here. 
A guide to allow pop-ups in Firefox can be found here.