Once purchased, the PreSonus Hub can be downloaded from your my.presonus.com account under My Products>Add-ons. If you already own Studio One 4 Professional, you can log into your my.presonus.com account and go to My Products>Software>Studio One 4 Professional and claim your copy. If you registered Studio One 4 Professional after December of 2019, you should already have the PreSonus Hub under My Products>Add-ons. There is a full Reference Manual built into the PreSonus Hub that explains the installation process in detail. Below is a screenshot that illustrates where you can find this manual, once you have downloaded and installed the PreSonus Hub.
***If you are on a Mac and are having a problem activating the PreSonus Hub, please refer to the following article to edit your permissions in the Shared folder of your User folder.