import os
from PySide6 import QtCore, QtQml, QtWidgets

if __name__ == "__main__":
    os.environ['QSG_RHI_BACKEND'] = 'd3d11'  # 'vulkan' vs. 'd3d11'

    app = QtWidgets.QApplication([])

    widget = QtWidgets.QWidget()
    widget.setWindowTitle('Widget')
    widget.resize(320, 180)
    widget.show()

    qml_engine = QtQml.QQmlApplicationEngine()
    qml_component = QtQml.QQmlComponent(qml_engine)
    qml_component.setData(
        QtCore.QByteArray(b"""
            import QtQuick.Controls 2.12
        
            ApplicationWindow {
                visible: true
                width: 320
                height: 180
                title: "QML"
            }
            """),
        QtCore.QUrl())
    qml_window = qml_component.create()

    app.exec_()