The flutter-view command is:
flutter-view [options] <directory [, directory...]>
Flutter-view scans for Pug and HTML files in one or more directories. For it to work, you need to pass where your source code is. Normally this is the lib directory of your project.
In almost every case, you want to go to your project directory and type:
flutter-view -w lib
This will tell flutter-view to watch your lib directory, and keep watching (-w) for changes.
When flutter-view creates or updates Dart files, it will tell you: