How to print Impress slides and notes to PDF with command line?


I need to print my Impress presentations slides and notes to PDF using a command line. I know I can print the slides as PDF (but not the notes) using

loffice --headless --print-to-file Presentation.odp

And one example found over the web says I can have a PDF with slides and notes, doubling the pages, with command

loffice --headless --convert-to pdf:"impress_pdf_Export:ExportNotesPages=True"  Presentation.odp

But it does not work (at least not for my case.) I am using Ubuntu 20.04 and LibreOffice

Please, do you know if 1) is it possible (to have notes PDF printed from an Impress presentation by command line) 2) being possible, what is the correct combination of switchs and options to do so?

Thank you all and best regards,