_fcm.configure(
      onMessage: (Map<String, dynamic> message) async {
        print("onMessage: $message"); // this is printed
        // static function:
        thisWeirdNotification(message['data']); // this is not called
      },
      ...
)

onMessage: {
  notification: {title: "yeaah", body: null},
  data: {channel_id: "chanel-name", info: "1", click_action: FLUTTER_NOTIFICATION_CLICK}
}

[√] Flutter (Channel master, 1.23.0-8.0.pre.124, on Microsoft Windows [Versione 10.0.19041.508], locale it-IT)
    • Flutter version 1.23.0-8.0.pre.124 at C:\src\flutter
    • Framework revision cbf1e135c4 (3 days ago), 2020-10-02 21:57:04 -0700
    • Engine revision 87a10f240f
    • Dart version 2.11.0 (build 2.11.0-181.0.dev)


[√] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    • Android SDK at C:\Users\_Apoleo\AppData\Local\Android\sdk
    • Platform android-30, build-tools 30.0.1
    • Java binary at: C:\Users\_Apoleo\AppData\Local\JetBrains\Toolbox\apps\AndroidStudio\ch-1\193.6626763\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
    • All Android licenses accepted.

[√] Android Studio (version 4.0)
    • Android Studio at C:\Users\_Apoleo\AppData\Local\JetBrains\Toolbox\apps\AndroidStudio\ch-1\193.6626763
    • Flutter plugin version 47.1.1
    • Dart plugin version 192.8052
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)

[√] Connected device (1 available)
    • sdk gphone x86 (mobile) • emulator-5554 • android-x86 • Android 11 (API 30) (emulator)

• No issues found!