Unresolved external symbol while trying to make custom widget from Qwt Plot in Visual Studio?

Question

Im trying to make custom widget in Qt with Qwt extension via Add >> New Item >> Qt Class. My enviroment :

• Visual studio 2022
• Qt 5.12.2
• Qwt 6.2.0
• Qt Creator 6.4.0

I successfully executed custom widget with QLabel base class but I can't successfully use QwtPlot class. I get this type of error:

I tried to find digestible answer but there is only something with moc_ files for Qwt. I added those in include file, but nothing works.

custom widget class waterlooo.h

#ifndef WATERLOOO_H
#define WATERLOOO_H

#include "qwt_plot_curve.h"
#include <vector>

#include <QwtPlot>
#include "qobject.h"

using std::vector;

class Waterlooo  : public QwtPlot
{
    Q_OBJECT

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


    void plotujkur(vector<float> x, vector<float> y, int fftecka);
};

#endif

custom widget class waterlooo.cpp

#include "waterlooo.h"

Waterlooo::Waterlooo(QWidget *parent)
    : QwtPlot(parent)
{
    this->setAutoFillBackground(true);
    this->setPalette(Qt::white);
    this->setCanvasBackground(Qt::white);


}

Waterlooo::~Waterlooo()
{}


void Waterlooo::plotujkur(vector<float> x, vector<float> y, int fftecka)
{
    QwtPlotCurve* curve1 = new QwtPlotCurve;
    curve1->setSamples(&x[0], &y[0], fftecka);
    curve1->setPen(QColor(Qt::green));
    curve1->attach(this);
    this->replot();
}