control a Qt/C++/QML GUI application running on a embedded device from a remote client application?

Question

Scenario: We have a Qt application(Qt 5.9.5,C++,QML,Ubuntu) running on a device (deals with telecommunications), which can also be viewed in a browser using webserver. All the operations done manually on the device have been visualized on the browser simultaneously.

Requirement: Now what we want to achieve is build a similar application(maybe web application) so that you execute it from a browser and simultaneously the application on the device should execute by itself. The device is just switched on initially. everything should be operated from the client application. What are the possible options?

We have started with Qt Remoteobjects to make a remote application but Qt version of device is older one when compared with Qt version of some functionalities in remote objects module. so using remote objects is not possible now.

Can Qt WebGL streaming helpful in this case?

Does QtWebchannel and websockets help by setting up communication with html/javascript application. Is it a possible solution?

Is virtual network computing (VNC) an option to think about in my scenario?

I have come across some concepts like Qt for WebAssembly, Web toolkit(Wt), Emscripten, Cutelyst web-framework, Qt for Automation - MQTT,OPC UA, KNX, CoAP . Do these really help at any point while developing a client application to control the QML GUI on a telecom. device?

Which of the options suits my scenario? I have been following Qt's blogs about these related topics. Still not sure which method is suitable?

Sorry for a lengthy explanation. Kindly provide some suggestions.

Thank you.