In your project directory, you should first install the necessary dependencies for using Amplify Push Notifications.

1. Open `pubspec.yaml` at the root of your Flutter project with a text editor.

2. Add the necessary libraries into the `dependencies` block:

```yaml
environment:
  sdk: '>=2.18.0 <4.0.0'

dependencies:
  amplify_auth_cognito: ^1.0.0
  amplify_flutter: ^1.0.0
  amplify_push_notifications_pinpoint: ^1.0.0
  flutter:
    sdk: flutter
```