How to implement adding point to QGraphicsView?

Question

Qt

Hello. Started learning Qt. There was such a question. Wrote a simple program that displays a lot of points on QGraphicsView. While I add all the points in the code itself through initialization.

void Graphic::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    std::vector<QPointF> points = {{10, 20}, {-30, 30}, {-40, 20}, {-50, 0}, {-60, 20}, {-75, 25},
                                   {-20, 10}, {-30, 15}, {25, 40}, {35, 35}, {50, 40}, {60, 70}};

    QPen pen(Qt::red, 4);
    painter->setPen(pen);
    for(auto& it = points.begin(); it != points.end(); ++it){
        painter->drawPoint(*it);
    }
    Q_UNUSED(option);
    Q_UNUSED(widget);
}

I want to make it possible to add points in the program itself. That is, let's say I enter coordinates through SpinBoxes, I press the button, and the point appears on the chart. How to make it easier?