With the pre-signed S3 URL obtained by the /voucher_url endpoint of one of the supported resources you can download the voucher of a successfull operation. Every URL has an expiration time of 5 minutes. Notice that this expiration time applies only to start the download process. After starting the download process, it can last more than the URL expiration time.
curl --request GET --url https://presigned-s3-url
When making a request to one of the pre-signed S3 URLs, you are interacting directly with AWS S3, so we have no control over errors and messages. Notice that errors returned by AWS S3 are sent as XML (not as JSON), so you need to consider this when parsing the content of an error response. You can read more about errrors returned by AWS S3 in the following documentation: Error Responses.