Enable PDF Stamper & Watermark Support for Amazon S3 Stored

We are currently using WP Download Manager with Amazon S3 as our primary storage solution for documents, which works very well for scalability and performance.

However, we’ve identified a key limitation when using the PDF Stamper and Watermark features.

At present, these features only function when files are stored locally on the server. When a document is stored on Amazon S3, the stamper and watermark tools are unable to process the file, as they rely on a local file path rather than a remote URL.