No idea how to configure cname for s3 buckets

[MrDienns]

I've gotten S3 working on my forums, but unfortunately I am unable to set up a cdn subdomain for my bucket. OVH is not clear about how this should be done. For reference, I've followed this guide: https://havecamerawilltravel.com/amazon-s3-bucket-cname/

I have a bucket named cdn.dyescape.com. I have created cdn.dyescape.com as a CNAME pointing to cdn.dyescape.com.s3.gra.perf.cloud.ovh.net. When accessing an image through the CDN subdomain (example https://cdn.dyescape.com/data/avatars/h/0/1.jpg?1676290270) I am seeing the below error;

<Error>
  <Code>InvalidRequest</Code>
  <Message>Invalid Request.</Message>
  <RequestId>txd90f03b160454969803b9-0063ea3e6a</RequestId>
  <Reason>Not S3 request</Reason>
</Error>

Accessing the same resource through the OVH provided URL works fine. Example: https://cdn.dyescape.com.s3.gra.perf.cloud.ovh.net/data/avatars/h/0/1.jpg?1676290270

I found this page which talks about subdomains for object storage on swift; https://docs.ovh.com/gb/en/storage/object-storage/pcs/link-domain/#with-cname. However, I don't know if this also refers to S3 buckets. The English on this page is also very poor and the overall writing makes it very difficult to follow or understand what's being done.

Further more, I cannot find the meaning of Not S3 request error anywhere. The only thing I found was some Python code for Swift where this error is thrown, but this doesn't clarify much either. https://github.com/openstack/swift/blob/master/swift/common/middleware/s3api/s3request.py#L686

Would appreciate some help getting this working. I'm willing to help rewrite / write new English documentation once I have it working. The current documentation is either missing, or not understandable.