curl --request POST \
  --url https://api.intelligence.io.solutions/api/r2r/v3/conversations/{id}/messages/{message_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "content": "<string>",
  "metadata": [
    "<any>"
  ]
}'

{
  "results": {
    "id": "id",
    "message": {
      "role": "user",
      "content": "This is a test message.",
      "name": "name",
      "function_call": {
        "key": "value"
      },
      "tool_calls": [
        {
          "key": "value"
        }
      ],
      "tool_call_id": "tool_call_id",
      "metadata": {
        "key": "value"
      },
      "structured_content": [
        {
          "key": "value"
        }
      ],
      "image_url": "image_url"
    },
    "metadata": {
      "key": "value"
    }
  }
}