Best way to register your H9 is downloading the H9 Control app for iOS/Android/Desktop and pair it with your H9. Then you’ll be able to create an Eventide account to register and control your H9.

Download the app here. Pick the version that works for you: https://www.eventideaudio.com/support/product/1151/installers

Videos 8 thru 10 walk you through the process of pairing your H9 and establishing an Eventide account:
https://youtu.be/I7N5IONscgs

To learn everything there is to know, follow the H9 Tutorials playlist: