curl --request POST \
  --url https://api.messages.dev/v1/files \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/octet-stream' \
  --data '"<string>"'

{
  "id": "<string>",
  "url": "<string>",
  "filename": "<string>",
  "mime_type": "<string>",
  "size": 123,
  "request_id": "<string>"
}