This allows generating PDF files from regular Contao pages via the mPDF PDF generator.
First you need to create a PDF generation configuration. If you only need the default settings, the following would suffice for example:
contao_pdf_generation:
configurations:
my_pdf_config: ~
Otherwise check the output of config:dump-reference contao_pdf_generation
for more options.
Next you will have to select a PDF generation configuration in your Contao page layout. You can find this in the Expert settings tab of your layout under PDF generation configuration. Only pages with a valid PDF generation configuration layout will be able to actually generate a PDF.
Next you will have to create a Generate PDF front end module in your theme. This module will output a form with a submit button that will trigger the PDF generation for the current page. Insert this module then either in your layout, or directly in your content somewhere.