Unable to run this project

[ostriandoni]

flutter run
Multiple devices found:
Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.19045.2486]
Chrome (web)      • chrome  • web-javascript • Google Chrome 109.0.5414.122
Edge (web)        • edge    • web-javascript • Microsoft Edge 110.0.1587.41
[1]: Windows (windows)
[2]: Chrome (chrome)
[3]: Edge (edge)
Please choose one (To quit, press "q/Q"): 2
Launching lib\main.dart on Chrome in debug mode...
../../AppData/Local/Pub/Cache/hosted/pub.dartlang.org/another_flushbar-1.12.29/lib/flushbar.dart:350:31: Error: Method 'addPostFrameCallback' cannot be called on 'SchedulerBinding?' because it is potentially null.
 - 'SchedulerBinding' is from 'package:flutter/src/scheduler/binding.dart' ('../flutter/packages/flutter/lib/src/scheduler/binding.dart').
Try calling using ?. instead.
    SchedulerBinding.instance.addPostFrameCallback(
                              ^^^^^^^^^^^^^^^^^^^^
Waiting for connection from debug service on Chrome...             31.5s
Failed to compile application.

I tried to execute all step by step at How to Use section but when I run this project, it return an error