How to start live activity by Push APNs?

I need to start an live activity from push APNs, the documentation says to use pushToStartTokenUpdates, but how I use or access this function?

pushToStartTokenUpdates is available as a static property for a given ActivityAttributes type. Assuming you have defined your attributes implementation, you can call Activity<YourAttributesType>.pushToStartTokenUpdates. This is different from how pushTokenUpdates is accessed since that property is tied to a specific instance of your Live Activity.

How to start live activity by Push APNs?
 
 
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