How to access Android localhost from Android?

I don't want access PC localhost! I want access Android localhost form Android. I have mixed application: logic in QtScript, C++ bridge to Qml. Qml is needed because we must have an web browser on the Android. Any way: I am sure I listen QWebSocketServer on localhost on port 4321. But my page can't connect to this server. I include permissions to access Internet and network state, and even for bluetooth (it complains about it). But it not works. Please tell me how to access android localhost server from android web browser?

thanks and best regards Jacek