Add dependencies.
for example:- import 'package:audioplayers/audio_cache.dart';
in the above package if we only use this package then it shows error
but if we add dependencies in pubspec.yaml
such as
dependencies:
flutter:
sdk: flutter
cupertino_icons: ^0.1.2
audioplayers: ^0.14.1
then click on packages get.
as you see this, I can also insert dependencies so if you insert dependencies along with your package then you are good to go.