Hello,
I have a page with sub-pages on my website, is there a way to add new sub-pages to my existing page?
Yes, you can add or remove sub-pages from their main page just by clicking on the “Change Album” button. You will see an album list window, there you can add and remove sub-pages from the main page.
Please see the article to know more about adding and removing sub-pages: https://help.slickpic.com/article/how-to-create-an-album-grid/