How can I customize ConnectycubeFlutterCallKit.showCallNotification screen?

Question

I need to display "incoming call" from camcorder on iOs/Android when the phone is locked (SIP call) with ringtone and/or vibration. I was able to show the "ringing call" on the lock screen using Connectycube-flutter-call-kit:

void _call() {
    Uuid uuid = Uuid();
    CallEvent callEvent = CallEvent(
        sessionId: uuid.v4(),
        callType: 0,
        callerId: 1,
        callerName: 'Test',
        opponentsIds: {101}.toSet(),
    );
    ConnectycubeFlutterCallKit.instance.init(
        onCallAccepted: () {},
        onCallRejected: () {},
        icon: 'app_icon',
        color: '#000000'
    );
    ConnectycubeFlutterCallKit.showCallNotification(callEvent);
}
...
ElevatedButton(
   onPressed: () {
      Future.delayed(const Duration(seconds: 10), () {_call(); });},
      child: Text('Test call')
   ),
...

But I don't understand how you can customize this screen. Is there such a possibility? On this screen, I need to add an image and buttons "Answer", "Open the door", "Ignore".

Help me please! Or maybe another plugin will suit me? There are many similar questions on stackoverflow.com like "Show notification on lock screen" but none of the recipes help so far :(

Thank you! :)