QRCoder: https://github.com/codebude/QRCoder
QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("This is QR Code", QRCodeGenerator.ECCLevel.Q);
QRCode qrCode = new QRCode(qrCodeData);
Bitmap qrCodeImage = qrCode.GetGraphic(20);
How to add text below QR code in the above qrCodeImage image object, like the below:
Your question should be approached as "How do I add text to a Bitmap?", and there are answers for it here: c# write text on bitmap