Export to Keynote

Hi, I’m new to Figma.
I have opened a “.deck” file in my Figma Mac app. Now I want to install the “Pitchdeck Presentation Studio” plugin to the Mac app because I heard it enables export to other formats.
Question 1: How can I install this plugin to the Mac app?
Question 2: After having it installed, how to open and export the “.deck” file to other formats?

Thank you all for your crowd wisdom!