I linked an Azure subscription but got an error when attempting to enable the 'ARM enabled' flag. Your Dynamics 365 Finance and Operations environment NEEDS to be ARM Enabled. So you won't get far without it. It was a pretty generic error in which you need MS assistance to see. Just know if you get an error and you're trying to enable the 'ARM enable' flag, give this process a shot.
I ran into some issues. Its pretty straight forward but the documentation was a little off so wanted to throw out a post about this just in case others find it helpful. If it helps one person, this 30 min effort was worth it.
Part 1: Authorizing
I have no pics for this so I'm just going to describe it.
I received an error when trying to authorize my LCS project. I had to add our 365 administrator to my project and have him click through the auth screens in the project. Once that was done, I was set.
This is what MS says:
Part 2: Let the Provisioning service spin up D365 environment
Here is my graphical walkthrough for you to follow along at home.
Here is the official documentation.