WebEngineScript sourceUrl: Can't open user script

elaf

I have tried to insert the qwebchannel.js script as WebEngineScript within a WebEngineView:

WebEngineView {
    id: webbrowser02
    WebEngineScript {
        injectionPoint: WebEngineScript.DocumentCreation
        id: qwebchannel
        sourceUrl: "qrc:///qwebchannel.js"
        worldId: WebEngineScript.MainWorld
    }
    userScripts: [qwebchannel]
}

The script file qwebchannel.js is defined within the resources:

<RCC>
    <qresource>
        <file>main.qml</file>
        <file>qwebchannel.js</file>
    </qresource>
</RCC>

Then, as I try to start, I've got the message:

QFSFileEngine::open: No file name specified
Can't open user script  QUrl("qrc:///qwebchannel.js")

What' going wrong? I'm using Qt 5.5 with QtWebView 1.1