start live activity via push notification pushToStartTokenUpdates

I have success with starting live activity from the server but I have some questions and problem

• first I get pushToStartTokenUpdates only once what if my user missed it? so I could not start from the server
• pushToStartTokenUpdates how long I can use? will it refresh the new token? for start live activity via push notification?
• does token I get from pushToStartTokenUpdates use for only start live activity event from server and can't use for update ?
• so if token get from pushToStartTokenUpdates for only start live activity via remote so how can I obtain the token for update ?