无法在Android上显示通知

<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.WAKE_LOCK" />

NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
if (!notificationManager.areNotificationsEnabled()) {
    Intent settingsIntent = new Intent(Settings.ACTION_APP_NOTIFICATION_SETTINGS)
        .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
        .putExtra(Settings.EXTRA_APP_PACKAGE, getPackageName());
    startActivity(settingsIntent);
}

Intent settingsIntent = new Intent(Settings.ACTION_APP_NOTIFICATION_SETTINGS)
    .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
    .putExtra(Settings.EXTRA_APP_PACKAGE, getPackageName())
    .putExtra(Settings.EXTRA_CHANNEL_ID, channelId); // 仅适用于Android 8.0及以上版本
startActivity(settingsIntent);