Any way to add Preview app to Harmony startup?

When setting up an activity for a Harmony remote for Roku, a startup channel can be set. Currently, I have my “Watch Tablo” activity set to the Tablo app, but I would rather make the preview app the default. Unfortunately, the app doesn’t show up in the list. Is this because it is a private app or does Logitech have to add it on their end?

Interesting Q - likely cause it’s a private channel.

Can you select any other private channels from your list?

Unfortunately, that’s the only private channel I have.