Need help compiling a new actor class

The tutorials seems to be well written, but I stumble here:

*Time to compile your project so you can add an instance of your new class to the level and test it out!

Because you have added a new UCLASS-decorated class and a new UPROPERTY-decorated variable, you will have to re-open your project in Unreal Editor after compiling to see the changes. Go ahead and close Unreal Editor now.

In the Toolbar, click on BasicClass to expand the Scheme dropdown. *

So, I should close the Unreal Editor, the app. But which Toolbar they do refer to, when I have closed the app?
Don’t understand this step, do they mean XCode?

The scheme dropdown is the one in Xcode in the top left corner, next to the “play” button. When you add a new class, or change an existing classes interface (add new methods, variables or change them), you need to close UE, rebuild your game code in Xcode (or Visual Studio), then reopen the project in UE. You need to close UE, because the old version of your game is already loaded in it, and you can’t hot swap if you change the interfaces.