Hi Wil,
You are able to print prototypes as PDFs from Axure RP, however the generated PDFs will not have any of the prototype’s interactive elements. To print a prototype as a PDF, go to “File > Print” in RP’s menu and then click “Print” in the print dialog that appears. This should bring up your system’s print dialog and either allow you to select the “Save as PDF” option there (for Mac) or a PDF printer you have installed on your computer (for Windows):
You’ll also be able to select the A4 paper size by clicking “Edit Paper Size” in Axure RP’s Print dialog.
If you’d like to share your prototypes as files while including their interactions, our best recommendation would be to generate the prototypes’ HTML files and then share those. A prototype’s HTML files (or “HTML output”) can be used to view prototypes offline and will include all of the prototype’s interactions as expected. You can generate a prototype’s HTML output by going to “Publish > Generate HTML Files” in the menu. If you’re not yet familiar with this feature, you can find some more information about it here:
https://www.axure.com/support/reference/viewing-and-sharing-html-output
https://www.axure.com/support/reference/html-generator
I hope this is helpful! I’ll also go ahead and submit a feature request for the ability to generate interactive PDFs to our PM team in the meantime.