Select "Export / Print" from the "File" menu. Then, you can export the presentation slides to PDF.
After starting the export from the file menu, an export-dialog opens:
- On the left, there is a dialog where you can choose export settings like the paper size, file name, etc.
- On the right, a preview of the presentation is shown
- After selecting the file name and other options, press the "Export" button to create the PDF file
When you did draw annotations on your slides when you were presenting, you can export them to PDF by checking the box "Export hand-drawn annotations"
The preview will then show the annotations, and they will also end up in the PDF file.