How to get gallery pro liked items?

Hi all,
I currently use a gallery pro to display images on my live site and I’m desperately searching for a way for my users to select their favorite pictures.
Using the “heart” icon, I thought I could retrieve the information somewhere (in a system collection or other) about “liked” pictures, but I don’t understand where this information is stored.
In addition, when I visit my live site, if I “like” a picture, the information seems to be lost when I come back to the same page later…
I have read a previous thread about this feature, where the event onItemClicked was mentioned, but this item is raised in the case we just expand the current image. Then, it cannot be a solution to track the “liked” items…
It seems very weird to provide a way to like gallery pro items while the information is not persisted, i.e. lost as soon as we go to another page, or without a way to implement an “onItemLiked” event handler, in the same way as “onItemClicked”.
Then, I certainly missed something, but does anybody knows how to track liked items or just the like action?
Thanks in advance