Get the SFSObject from parameter (Smartfox server)

I send a message with SFSObject to smartfox server server as following script

public void SendMessageToOther(SFSObject dataObj) {

Room room = smartFox.LastJoinedRoom;

smartFox.Send(new PublicMessageRequest(dataObj.GetUtfString("type").ToString()+":"+dataObj.GetFloat("PositionIdx").ToString(),dataObj));

 }

And I use the following script to parse the data

 void OnPublicMessage2(BaseEvent evt) {
     try {
         string message = (string)evt.Params["message"];
         User sender = (User)evt.Params["sender"];
         
         // We use lock here to ensure cross-thread safety on the messages collection 
         lock (messagesLocker) {
             messages.Add(sender.Name + " said " + message);
         }
          ISFSObject dt = (SFSObject)evt.Params["params"];
         //Debug.Log(dt.GetFloat("type").ToString());
         chatScrollPosition.y = Mathf.Infinity;
         Debug.Log("User " + sender.Name + " said: " + message);
         if(!sender.IsItMe)
         {    if(message.Split(':')[0]=="moveEyeball")
             parentObject.SendMessage("EyeBallMove",message.Split(':')[1]);
             if(message.Split(':')[0]=="movePage")
             gameObject.SendMessage("MoveToPosition",message.Split(':')[1]);
         }//MoveCameraToPositon
         
     }
     catch (Exception ex) {
         Debug.Log("Exception handling public message: "+ex.Message+ex.StackTrace);
     }
 }

I can get the message string from the parameter but I can't get SFSObject from the parameter Does anyone know how to solve this problem?