The Platforms page allows you to select the platform to include in the generated project. By default, the generated project can run on Android, iOS, and the Web without any additional effort. However, to run your app on the desktop, you need to enable a platform (e.g., MacOS, Windows, Linux) from this page.
After selecting the platforms, you can download the generated project and run the app using the testing instructions on the following page:

Advanced iOS Settings

If the app is specifically designed for an iPhone and doesn't provide a good user experience on an iPad, you might want to Disable iPad Support.
Disable iPad support