Well, There's no `robots.txt` in s3.amazonaws.com. That's all.
```
~ $ curl -i https://s3.amazonaws.com/robots.txt
HTTP/1.1 403 Forbidden
x-amz-request-id: R92SWEWBCTEW0ZTV
x-amz-id-2: FV4H1wGNhEqgyuB4pbrKNeAxFrSwB8vCkCOFOKDuswmW0CbfoI6W7FbLp1aLWQoyLG543A6FmMw=
Content-Type: application/xml
Transfer-Encoding: chunked
Date: Sat, 23 Mar 2024 08:15:22 GMT
Server: AmazonS3
AccessDenied
```