code: @SuppressWarnings("unused")
      public static void createNotificationChannelGroup(final Context context, final String groupId, final CharSequence groupName) {
          final CleverTapAPI instance = getDefaultInstanceOrFirstOther(context);
          if (instance == null) {
              Logger.v("No CleverTap Instance found in CleverTapAPI#createNotificationChannelGroup");
              return;
          }
          try {
              if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                  instance.postAsyncSafely("creatingNotificationChannelGroup", new Runnable() {
                      @RequiresApi(api = Build.VERSION_CODES.O)
                      @Override
                      public void run() {
  
                          NotificationManager notificationManager = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
                          if (notificationManager == null) return;
                          notificationManager.createNotificationChannelGroup(new NotificationChannelGroup(groupId, groupName));
                          instance.getConfigLogger().info(instance.getAccountId(),"Notification channel group " + groupName.toString() + " has been created");
  
                      }
                  });
              }
          } catch (Throwable t){
              instance.getConfigLogger().verbose(instance.getAccountId(),"Failure creating Notification Channel Group", t);
          }
      }
docs: Launches an asynchronous task to create the notification channel group from CleverTap
  <p/>
  Use this method when implementing your own FCM/GCM handling mechanism. Refer to the
  SDK documentation for usage scenarios and examples.
  
  @param context A reference to an Android context
  @param groupId A String for setting the id of the notification channel group
  @param groupName  A String for setting the name of the notification channel group