I've started the tutorial, but I haven't proceeded very far.... How do I switch to independent realms map mode?
That part of the tutorial seems to be currently broken.
In a recent version (v1.09), selecting map modes changed. What you're supposed to do is to click on the + button:
Which will show the various map modes that you can use (independent realms is the second button with the image of a shield):
But doing this doesn't work in the tutorial right now. I think you'll have to skip the rest of this tutorial and continue with other tutorials. (There is a ▶ button for that in the lower left corner.)