The Portal's Screens configuration page shows all the screens accessible by the customer through the portal.
You can also see the status of whether or not a Sign In is required for each. By default, every new screen added to the portal requires the contact to be authenticated before viewing a page.
You can, however, make a screen available to your customer without first signing in. If you select a screen in the grid, it will take you to the security settings for that screen.
By checking Allow guests to view screen without signing in, the screen you selected will now be open without authentication.
When should you allow a guest to sign in or not? This is dependent on the situation. In our stock screens, you will notice viewing transactions do not require a sign in.
As a best practice:
If a screen is for viewing or paying - Allow guests to view screen without signing in
If a screen requires creating, deleting, or editing - Do not allow without signing in