If I may say so, OSMC does does not make this very intuitive for a first-time user, compared to LibreELEC, so I sympathise with the OP for not having found it at first.
We try and make it more user friendly, in that an Internet connection is not needed to install any binary add-ons.
It’s possible that you are just used to the LibreELEC approach of having to install binary add-ons via the Addon manager which is not typical on all platforms, such as Ubuntu.
The idea of pre-installation of the addon makes sense. But when you do a clean install of OSMC and go to the TV part of the main menu, you see a message about it not being set up and a button is available to take you to addons, which in my experience the user then has to figure out what to do next, as when you click you are taken to the addon manager, but not directly to the installed addons to find the TVHE client. On a couple of occasions this has driven me to distraction with OSMC, as I have to remember that you need to go back to the installed addons first. We each have our own view on what is intuitive, this is an area where I think LE is just more intuitive. Also LE does not have the separation of the TVHE server in an “app store”, for me it takes amore consistent approach.