I set this attribute:

setAttribute(Qt::WA_AcceptTouchEvents);

I built the APK file and ran it on Android but the counter of touches isn't changed:

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QtGui/QTouchEvent>
#include <QtWidgets/QLabel>
#include <QtWidgets/QWidget>

class Widget : public QWidget
{
    Q_OBJECT

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

protected:
    bool event(QEvent *event) override;

private:
    QLabel *m_counterOfTouchesLabel;
    int m_counterOfTouches = 0;
};
#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include <QtWidgets/QHBoxLayout>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    setWindowTitle("Touch Coords");
    resize(300, 300);
    setAttribute(Qt::WA_AcceptTouchEvents);

    QHBoxLayout *hbox = new QHBoxLayout(this);
    m_counterOfTouchesLabel = new QLabel("Counter of touches: 0");
    hbox->addWidget(m_counterOfTouchesLabel);
    setLayout(hbox);
}

Widget::~Widget()
{
}

bool Widget::event(QEvent *event)
{
    switch (event->type())
    {
        case QEvent::TouchBegin:
            m_counterOfTouches++;
            m_counterOfTouchesLabel->setText("Counter of touches:" +
                QString::number(m_counterOfTouches));
            break;
        default:
            break;
    }

    return true;
}