Acces to HTML element in a WebEngineView

[Fab01]

Hello all, i try to figure it out how works QML WebEngineView and how I can acces html element in it (read/write).
The documentation is not clear for me, so here what I want to do.

In a WebEngineView, I load an html page with only two INPUT elements in it, a "text" element and a "password" element.

1. I want to show a QML keyboard of my own when a mouseclic event occur only in these two elements

2. How can I automatic fill the values of these elements ?

I guess runjavascript method is what I need but I don't understand how it could interact with my QML.

[Fab01]

I tried this:

var js="function testclic(){var index, inputs; inputs = document.getElementsByTagName('INPUT');\
                                                    for (index = 0; index < inputs.length; ++index)\
                                                    {\
                                                        inputs[index].onfocus = function()\
                                                        {\
                                                            return(33);\
                                                        }\
                                                    } return(-1);} testclic()"
 
 web_view.runJavaScript(js,function(result){console.log("res "+result);})

but I never reach the onfocus...some advices ?