Hey there, and thanks for your interest in Live Activities and Dynamic Island!
Live Activities are implemented using the ActivityKit framework, which was available in iOS 16 beta 4 and iOS 16 beta 5. The ActivityKit framework is not included in iOS 16 RC, and is not included in Xcode 14 RC. ActivityKit will be included in an update to iOS 16 coming later this year, as mentioned in
this News and Updates post. Once ActivityKit is available in an update to iOS 16, you'll be able to implement Live Activities and interact with them in Dynamic Island.
We're excited to see what you build with this new functionality!