Error: No named parameter with the name 'isAlwaysShown'.

[user97116]

Launching lib/main.dart on RMX1801 in debug mode...
/home/amar/.pub-cache/hosted/pub.dev/vs_scrollbar-0.2.1/lib/vs_scrollbar.dart:143:11: Error: No named parameter with the name 'isAlwaysShown'.
isAlwaysShown: isAlwaysShown,
^^^^^^^^^^^^^
/home/amar/.pub-cache/hosted/pub.dev/vs_scrollbar-0.2.1/lib/vs_scrollbar.dart:174:14: Error: The getter 'isAlwaysShown' isn't defined for the class '_MaterialScrollbar'.

• '_MaterialScrollbar' is from 'package:vs_scrollbar/vs_scrollbar.dart' ('/home/amar/.pub-cache/hosted/pub.dev/vs_scrollbar-0.2.1/lib/vs_scrollbar.dart').
  Try correcting the name to the name of an existing getter, or defining a getter or field named 'isAlwaysShown'.
  widget.isAlwaysShown ?? _scrollbarTheme.isAlwaysShown ?? false;
  ^^^^^^^^^^^^^
  /home/amar/.pub-cache/hosted/pub.dev/vs_scrollbar-0.2.1/lib/vs_scrollbar.dart:174:47: Error: The getter 'isAlwaysShown' isn't defined for the class 'ScrollbarThemeData'.
• 'ScrollbarThemeData' is from 'package:flutter/src/material/scrollbar_theme.dart' ('/home/amar/snap/flutter/common/flutter/packages/flutter/lib/src/material/scrollbar_theme.dart').
  Try correcting the name to the name of an existing getter, or defining a getter or field named 'isAlwaysShown'.
  widget.isAlwaysShown ?? _scrollbarTheme.isAlwaysShown ?? false;
  ^^^^^^^^^^^^^
  Target kernel_snapshot failed: Exception

FAILURE: Build failed with an exception.

• Where:
  Script '/home/amar/snap/flutter/common/flutter/packages/flutter_tools/gradle/src/main/groovy/flutter.groovy' line: 1297

• What went wrong:
  Execution failed for task ':app:compileFlutterBuildDebug'.

Process 'command '/home/amar/snap/flutter/common/flutter/bin/flutter'' finished with non-zero exit value 1

• Try:

Run with --stacktrace option to get the stack trace.
Run with --info or --debug option to get more log output.
Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 23s