I’ve managed to get this working (of sorts), so I can use the FileUploadNoGUI function ok. My bucket and IAM permissions are all ok, as well as CORS, so I can upload and delete and my S3 bucket is set as Access: Only authorised users of this account, but I cannot download and open the files. The only way I can do this is by unblocking all public access, which means the URL can simply be put into a browser for the file to download too.
Is the download object not passing the IAM credentials? I’m no expert so this may not make any sense, but I hope you can understand it.
Thanks