I don't see the new Site Admin menu
You login to your application but you're unable to see the Site Admin menu.
You're not login into the application with a Site Admin user.
How to solve
1. Go to the (legacy) Site Admin, and find the admin or your Site Admin user you typically use to log in to your server.
2. Log in to your application with a user you from step 1.
3. Now you should see this menu to the left of the application.
If you don't see this menu, it's because you've logged in, using a user that is not a Site Admin user.
To add the Site Admin user, as a member of an application, follow the steps here (only the part Adding the user to the new application).