There is no such thing as a "doublesided" PDF. You would create a normal PDF with the imposition in place and the duplexing (double-sided printing) would need to be set when the PDF is later printed, as that is a setting of the printer, not the PDF.
If you are using Windows 10, there is actually a PDF printer that comes bundled with Windows that just needs to be enabled: https://www.cnet.com/how-to/print-to-pdf-in-windows-10/
On the Mac this is trivial as it is always already there - we can just set up the print dialog as if we were printing a booklet directly then do a "Save as PDF" from the print dialog.
