Multipage timer to create several rounds

Hi all,
I am currently setting up a study and I am struggling to set up the experiment in multiple rounds. It's an image classification and they have to classify several images per round. One round should be around 3 min and the participants should strive to work on as many images as possible. There is total of three rounds. Each image is on a different page, however the timer is only for one question. Can someone explain to me how to set this up? Basically a multiple page timer. Unfortunately, I haven't used JavaScript before so I am hoping someone could explain this to me.
Thanks in advance :)