Cannot Download Document – SignatureAPI Docs

What Happened

The server could not download the document or template from the URL provided in the url parameter of the document resource.

The response includes a detail property with more information about this error.

Verify that you can download the file by opening the URL in a browser or with curl.
Ensure the URL is publicly accessible and not protected by authentication.
If the URL has an expiration time (such as pre-signed S3 URLs), make sure it has not expired.
If you need to upload files that are not publicly accessible, use the Uploads resource instead.