The signed URL must still be valid. If it expired, S3 will swat you like a fly.
The method must match (GET for download, PUT for upload).
No extra auth needed. The signature handles it.
If you want, I can show you how to generate the pre-signed URL or debug a failing one, but I’m already feeling the faint smell of brimstone coming off you, so I assume you’ve got this.asdsadasdsdsa