Can I use a guest network?

Sometimes. A guest network that only has its own password works like any other. Many, though, add “client isolation”, which keeps devices on it from seeing each other, so your phone on the main network cannot open the ticker’s settings page, or a sign-in page that the ticker cannot pass. The setup card’s tip is blunt: Placing me on a Public or Guest probably won't work. Use the main network unless you know the guest one passes traffic. See Guest networks.