When is the FCM HTTP v1 API supported?

[camry]

When is the FCM HTTP v1 API supported?

url: https://firebase.google.com/docs/cloud-messaging/server?authuser=0#choose

Example:

curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
  "notification": {
    "title": "FCM Message",
    "body": "This is a Firebase Cloud Messaging Topic Message!",
  },
  "topic" : "foo-bar"
}' "https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1"

[weierophinney]

@mwillbanks Any ideas for this?