1. In order to allow printing of an Issue, first navigate to the title you wish to enable it for.
You will notice a toggle called "Enable Printing of PDF" , turn the toggle to "On" to enable.
2. To print an issue when viewing it simply click the dropdown menu  located in the top right corner and select "Print Pages" 
3. This will bring up a print menu, you can select which pages you would like to print/download or choose all pages and click "Print" [1.
You will notice a progress bar beginning to fill.