dompdf support:
  The dompdf tool produces results that are more faithful to the HTML
  printer-friendly page. Good support of CSS 2.1 and partially CSS3.

  The recommended version of this tool is 0.8.2 or newer since it is fully
  compatible with PHP 7.1, and security support has ended for all prior
  versions of PHP as of December 31, 2018.

  1. Download dompdf from https://github.com/dompdf/dompdf/releases. Make
  sure to download the full release zipfile. If you download only a source
  code file, you will also need to download and install the php-font-lib.
  2. Extract the contents of the downloaded package into one of the
  supported paths.
  3. If upgrading from version 0.6 or older, visit the settings page on your
  site at http://example.com/admin/config/user-interface/print/pdf and select
  the new path for the "PDF generation tool" setting.
  4. If using dompdf 0.6 or 0.5, check if dompdf_config.inc.php fits your
  installation. In 99% of cases, no changes are necessary, so just try to use
  it and only edit anything if the PDF generation fails.
  5. If  using dompdf 0.6 or 0.5, delete the dompdf.php file as it contains a
  security vulnerability. Delete also the index.php and www folder, as they are
  not needed.
  6. Grant write access to the lib/fonts directory for your webserver user.
  7. If you're using dompdf 0.6, you can try to enable the Unicode support, but
  you'll need to add some Unicode fonts. See
  http://groups.google.com/group/dompdf/browse_thread/thread/9f7bc0162b04d5cf
  for further info on this.
  8. Review the recommendations for securing your dompdf installation at
  https://github.com/dompdf/dompdf/wiki/Securing-dompdf
  9. Check https://dompdf.github.io/ for further information.
