QT 6.6.0. C++ camera issue

I am new to QT and I can’t figure out why my code is not working. It does not matter whether the camera is connected to the PC or not, my app crashes. The crash is probably caused by m_captureSession related code lines in mainwindow.cpp.

mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtCore>
#include <QtGui>
#include <QtWidgets>
#include <QtMultimedia>
#include <QtMultimediaWidgets>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QScopedPointer<QCamera> m_camera;
    QScopedPointer<QMediaCaptureSession> m_captureSession;
};
#endif // MAINWINDOW_H

mainwindow.cpp:

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_camera.reset(new QCamera(QMediaDevices::defaultVideoInput()));
    m_captureSession->setCamera(m_camera.data());
    m_captureSession->setVideoOutput(ui->cameraViewfinder);
    m_camera->start();
}

MainWindow::~MainWindow()
{
    delete ui;
}

.pro file:

QT       += core gui multimedia multimediawidgets

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    mainwindow.h

FORMS += \
    mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

Camera permission is granted and the QCamera object successfully connects to my device