Indigo Layout Topic Icons: How to select topics?

Hello, everyone!

I am a very new Robohelp user, so this is probably a painfully easy question--at least I hope! I am working on a project and currently only two of the topic icons are appearing on the main page of the Indigo layout, despite the fact that I have 5 topic tiles chosen in the customization settings. Why aren't new topics I have created appearing there? Do I have to select those manually, and if so where do I do that?

Any and all help is vastly appreciated!

Thanks,

-Keeley