This is a single page link that will be shown in the Sidebox.

There are no additional pages or links associated with this page as there is no Chapter.

Later, if you want to expand on this link you can add a Chapter and TOC settings and build a group.

Notice that the Previous/Next and TOC automatically disable when there isn't a Chapter. Even with a Chapter, there must be more than one (1) related link or page in the group before these will display.