Showing a progress indicator, used here: https://www.flutterclutter.dev/flutter/tutorials/displaying-a-prorgess-indicator/2020/37/

progess_indicator_03.dart

  void showLoadingIndicator([String text]) {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          content: LoadingIndicator(
            text: text
          ),
        );
      },
    );
  }