Choosing the right extension point
As the app developer, you decide which section of your app appears in which extension point. This is useful because most apps offer a variety of functionalities, some of which are more suitable to display in one user interface than in another.
For example, a SitecoreAI translation plugin could include an authentication section and a feature for adding pages to a translation project. You could choose the full screen extension point for the authentication section while the page-specific translation feature is best to display in the Page builder context panel.
You first choose extension points when you configure your custom or public app in the Cloud Portal. Although extension points and API access are not dependent on each other, you usually need to choose certain APIs for certain extension points.
You can update your app's extension points any time as your app requirements change.