Web2PDF
This Extension renders the pagecontent to a PDF file. It supports css and uses the library mPDF.
MPDF
mPDF is a PHP library which generates PDF files from UTF-8 encoded HTML. It is based on FPDF and HTML2FPDF with a number of enhancements. More: https://mpdf.github.io/
mPDF QR code library
QR code generating library with HTML/PNG/mPDF output possibilities. This is based on QrCode library bundled with mPDF until v8.0, made by Laurent Minguet. It is provided under LGPL license.