Update Live Activity using remote push notification in SwiftUI - swift

Question

I am trying to update live activities using remote push notifications.
I am creating a live activity like this:
do{
let activity = try Activity<LiveMatchesAttributes>.request(attributes: attributes, contentState: state, pushType: .token)
print("Activity Added Successfully. id: \(activity.id)")
Task {
for await data in activity.pushTokenUpdates {
let myToken = data.map {String(format: "%02x", $0)}.joined()
print("pushToken", myToken)
}
}
}catch{
print(error.localizedDescription)
}
The live activity shows up in the notifications center and the pushToken can also be received.
Now I am trying to update the live activity using remote notifications. The code for that looks like this:
exports.updateLiveActivities = functions.https.onRequest((req, res) => {
const fcmToken = "fcmToken"
const apns = {
headers: {
"apns_push_type" : "liveactivity",
"apns_topic" : "bundle_id.push-type.liveactivity",
},
"payload": {
"aps": {
"timestamp" : Date.now(),
"event": "update",
"content-state": {
"event": "start"
},
"alert": {
"title": "Race Update",
"body": "Tony Stark is now leading the race!"
}
},
}
}
const message = {
token: fcmToken,
apns: apns
}
admin.messaging().send(message).then((response) => {
// Response is a message ID string.
console.log('Successfully sent message:', response);
res.send("ok")
// return res.send("ok");
}).catch((error) => {
console.log(error)
return res.send(error.code);
});
});
Sending the remote notification works because the "alert" is appearing on my phone but the live activity is not getting updated. Any ideas where to insert the received "pushToken" for the live activity?