Unable to run Qt WebView sample code

[jean_b]

Hello,

I have built and installed QtWebKit and QtWebView from source https://code.qt.io/cgit/ at tag 5.12.5.
I have built the sample project minibrowser.pro.
When I run the project, it says :

No WebView plug-in found!

I'm running Ubuntu 19.04 and using Qt5.12.5.
The WebView libraries are installed in <QT_INSTALL_DIR>/lib
Plugins loaded: libqwbmp, libqwebp.
Another message says:

On QtCore unload, "/usr/local/Qt-5.12.5/qml/QtWebView/libdeclarative_webview.so" was leaked, with 2 users

Any help would be precious ;)