Turning Pages on Chromebook

Hi,

I have just added Digital Editions to my Chromebook via the Google Play store and successfully downloaded two ebooks from my university library. However, I cannot for the life of me work out how on earth you turn the page?! A fairly essential function! I've tried pressing pretty much every key on the keyboard and am at a complete loss. My chromebook isn't a touchscreen so I cannot swipe as I do on my phone/kindle. Any tips - or is it a no go 😞

L