How to start session globally?

"global variable" is not in OOP style.. Usually when you want something you load it somehow.
This will only guarantee that session is started ..
From that point to set/get things in the session is up to you. $_SESSION is available to get it and in the few places where you will set something you can simple get the same

Code:

$session = \Config\Services::Session();

Yes I understand and that's now what I want (to make that available global)
The aim is
To start session for all pages
To connect to database - required for all pages

At the moment, I can do that above fine by creating a base controller and extending to it.