using IronQr;
using IronPdf;
using IronSoftware.Drawing;

// Generate QR code and save as bitmap
AnyBitmap qrBitmap = QrWriter.Write("hello world").Save();

// Load an existing PDF document
PdfDocument pdf = PdfDocument.FromFile("sample.pdf");

// Stamp the QR code onto the first page at position x=505, y=20 (top-right corner)
pdf.DrawBitmap(qrBitmap, pageIndex: 0, x: 505, y: 20, desiredWidth: 70, desiredHeight: 70, pixelFormat: PixelFormat.Format32bppArgb, ignorePageRotation: false);

// Save the modified PDF
pdf.SaveAs("output.pdf");