curl --request GET \
  --url https://api.withflex.com/v1/files \
  --header 'Authorization: Bearer <token>'

{
  "files": [
    {
      "file_id": "<string>",
      "purpose": "account_requirement",
      "size": 123,
      "created_at": "<string>",
      "filename": "<string>",
      "type": "<string>",
      "expires_at": "<string>"
    }
  ]
}