When you start a new project in Flex, your experience will begin with a single page, but you can add additional pages if your content requires more.
To add a new page to your experience in Flex:
Navigate to the Layers and Pages Panel on the left side of the Flex workspace
Select the + Add page button next to "Pages"
Once created, you can rename your new page by double-clicking on it in the Pages and Layers Panel and entering a new name.
Additionally, you can select the Page options menu (...) while hovering to the right side of the page name in the Layers and Pages Panel to adjust its Settings, Rename the page, or Delete it.