lib folder is the entry points of the projects.
Based on https://codelabs.developers.google.com/codelabs/flutter-codelab-first?hl=ko#0
Using in flutter-tools.nvim
run: :FlutterRun
Maybe use this project as a base for work with ble in flutter.
This lib https://github.com/PhilipsHue/flutter_reactive_ble should be helpful.
Add this to pubspec.yaml file.