I'd like to inquire about the services of creating QR codes for PDF documents, and how it works, specifically where documents are stored, how long they are retained, and security policies if your services are used.

Your PDFs are stored in cloud, we internally use services of GCP, AWS and Azure. Your data is 100% secure, only the main and subaccounts (if made admin) can access the information.

However, the PDF location in the QR code is public (but non-guessable) to allow users who are scanning the QR code to be able to download the PDF.