How can enable HotSpot on android 11 device by delphi code

[GSan 1]

Hi everyone, I'm trying to enable and disable hotspot on android11 device with Delhpi 11 but I don't understand what I'm doing wrong....

this is my code:

procedure TForm1.Button2Click(Sender: TObject);
var
WifiManagerObj: JObject;
WifiManager: JWifiManager;
Mycallback: JWifiManager_LocalOnlyHotspotCallback;
 startedres:JWifiManager_LocalOnlyHotspotReservation;
handler: JHandler;
begin

 WifiManagerObj := SharedActivityContext.getSystemService(TJContext.JavaClass.WIFI_SERVICE);
 WifiManager := TJWifiManager.Wrap((WifiManagerObj as ILocalObject).GetObjectID);


Mycallback:= TJWifiManager_LocalOnlyHotspotCallback.Create;
 startedres:=TJWifiManager_LocalOnlyHotspotReservation.Create;

  WifiManager.startLocalOnlyHotspot(Mycallback,handler);

  Mycallback.onStarted(startedres);

end;

some idea...

thank you

GS