Use environmental variables in flutter

• Install flutter_dotenv package
• Create a .env file in the root of your project
• Add your variables to the .env file
• In order for the package to load .env file, add it to asset bundle in pubspec.yaml

  flutter:
    assets:
      - .env (path to the file where env is stored)

• Load the contents of env into flutter, by adding this is main.dart

 void main() async {
    await dotenv.load();
    runApp(const MyApp());
  }

• Access the env variable like this dotenv.env['APP_ENVIRONMENT']