On the Panels, you will be able to see different formats, that can be edited by changing the "Edit" option.
Change the Panel to Center
In the table on the bottom, you can choose different displays to be under Page, Mobile, MobileLandscape (if needed, create different displays to use here)
2. Changing Layouts in Runtime
In the Displays → Draw, add two buttons
Double-click the first button, and under Label Text add: Startup Layout
Go to Dynamics, set Actions and choose OpenLayout
In Layout, type Startup
Repeat the procedure for the second button, but this time, the configuration is below: