curl --request POST \
  --url https://api.altur.io/api/v1.0/message \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "agent_id": "<string>",
  "end_user_id": "<string>",
  "content": "<string>"
}
'

{
  "thread": {
    "id": "<string>",
    "agent": {
      "id": "<string>",
      "name": "<string>"
    },
    "end_user": {
      "id": "<string>",
      "display_name": "<string>",
      "info": "<string>"
    },
    "integration": {
      "id": "<string>"
    },
    "updated_at": "2023-11-07T05:31:56Z",
    "active": true,
    "blocked": true,
    "tags": [
      {
        "id": "<string>",
        "name": "<string>"
      }
    ],
    "assigned_to": [
      {
        "id": "<string>",
        "email": "<string>",
        "first_name": "<string>",
        "last_name": "<string>"
      }
    ]
  },
  "messages": [
    {
      "thread_id": "<string>",
      "sent_at": "2023-11-07T05:31:56Z",
      "content": "<string>",
      "media": "<string>",
      "sent_by_user": "<string>",
      "read": true
    }
  ],
  "in_response_to": {
    "thread_id": "<string>",
    "sent_at": "2023-11-07T05:31:56Z",
    "content": "<string>",
    "media": "<string>",
    "sent_by_user": "<string>",
    "read": true
  }
}