Here are some instructions. I’m on Windows, so your Mac interface might look slightly different.
- In the main window, go to the pull-down menus and click on File → Export… The Export window will appear.
- For Export format, choose Anki Deck Package (.apkg). Choose which decks you wish to export using the Include drop-down.
- Click the Export… button. Then choose where to save the exported package.
Now send the exported file to your friend. They can import it using File → Import… in the main window’s pull-down menus. See first screenshot above.