Request presigned URLs for the remaining chunks

This method generates new presigned URLs for specific chunks that require uploading. Use this endpoint in the following situations: - Your initial URLs have expired (URLs expire after one hour). - The initial set of presigned URLs does not include URLs for all chunks. - You need to retry failed chunk uploads with new URLs. To specify which chunks need URLs, use the `start` and `count` parameters. For example, to generate URLs for chunks 21 to 30, use `start=21` and `count=10`. The response will provide new URLs, each with a fresh expiration time of one hour.