The first time you run this (and subsequently when the DevTools package
is updated), you are prompted to activate or upgrade DevTools.

Clicking the Open button uses pub global activate to activate
the DevTools package for you. Next, DevTools launches in your browser and
automatically connects to your debug session.

While DevTools is active, you’ll see them in the status bar
of VS Code. If you’ve closed the browser tab,
you can click the status bar to re-launch your browser, so long
as there’s still a suitable Dart/Flutter debugging session available.