In iOS 17.2 we can start a live activity by push, and the document says:
When the system receives the ActivityKit push notification on a device, it starts a new Live Activity, wakes up your app, and grants it background run time to allow you to download assets that the Live Activity needs.
My problem is, in which callback can I be notified a live activity will be start by a push, so I can download some web contents such as images before the live activity be rendered.