Your My.Presonus app on your phone shows you what is registered in your account.
We don't have the ability for you to install applications on your Mac / PC from looking at your items in the my.presonus.com app on your phone. Your local computer won't show these because you need to download and install them from your account at
https://my.presonus.com.
From your Mac, open a browser, go to
https://my.presonus.com and click on "My Products",
Under Software will be listed Studio One and/or Notion if you purchased it.
Under Add-Ons will be listed any effects or loop libraries that either came free or you've purchased.
Click on each one of these to get details and to download them. Once on your local machine open your downloads folder, double click them to install them.
Once installed, you can then run Studio One (or Notion) to use the program and through the application you will be able to load the content.
