curl --request POST \
  --url https://api.hubmessage.io/v1/channels/{channelId}/messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "recipient": {
    "identifier": "5511999999999"
  },
  "content": {
    "type": "AUDIO",
    "attachments": [
      {
        "url": "https://actions.google.com/sounds/v1/alarms/digital_watch_alarm_long.ogg"
      }
    ]
  }
}
'

{
  "messageId": "wamid.HBgNNTU0NDk3MDUwNzg1FQIAERgSM0"
}