error in flutter

[sadiabbas1122]

C:\src\flutter\bin\flutter.bat --no-color build apk
The plugin flutter_facebook_login uses a deprecated version of the Android embedding.
To avoid unexpected runtime failures, or future build failures, try to see if this plugin supports the Android V2 embedding. Otherwise, consider removing it since a future release of Flutter will remove these deprecated APIs.
If you are plugin author, take a look at the docs for migrating the plugin to the V2 embedding: https://flutter.dev/go/android-plugin-migration.

Building with sound null safety

Running Gradle task 'assembleRelease'...
Warning: Mapping new ns http://schemas.android.com/repository/android/common/02 to old ns http://schemas.android.com/repository/android/common/01
Warning: Mapping new ns http://schemas.android.com/repository/android/generic/02 to old ns http://schemas.android.com/repository/android/generic/01
Warning: Mapping new ns http://schemas.android.com/sdk/android/repo/addon2/02 to old ns http://schemas.android.com/sdk/android/repo/addon2/01
Warning: Mapping new ns http://schemas.android.com/sdk/android/repo/repository2/02 to old ns http://schemas.android.com/sdk/android/repo/repository2/01
Warning: Mapping new ns http://schemas.android.com/sdk/android/repo/sys-img2/02 to old ns http://schemas.android.com/sdk/android/repo/sys-img2/01
lib/pages/add_message_page.dart:1:1: Error: A library can't opt out of null safety by default, when using sound null safety.
// @Dart=2.9
^^^^^^^^^^^^
Error: Cannot run with sound null safety, because the following dependencies
don't support null safety:

• package:flutter_facebook_login
• package:flutter_emoji

For solutions, see https://dart.dev/go/unsound-null-safety

FAILURE: Build failed with an exception.

• Where:
  Script 'C:\src\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 1005

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

Process 'command 'C:\src\flutter\bin\flutter.bat'' 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 36s
Running Gradle task 'assembleRelease'... 37.3s
Gradle task assembleRelease failed with exit code 1

[pavelsust]

Facing the same issue. any update from author???