I’m trying to build a simple image viewer app with pyqt6 designer using pyuic6 the code files are to be open with file menu i’m using QFileDialog to open the files but when I run the code the dialog appears instead of the UI please tell me what did I do wrong ?

here is the code

type here
# Form implementation generated from reading ui file 'test.ui'
#
# Created by: PyQt6 UI code generator 6.8.0
#
# WARNING: Any manual changes made to this file will be lost when pyuic6 is
# run again.  Do not edit this file unless you know what you are doing.


from PyQt6 import QtCore, QtGui, QtWidgets
from PyQt6.QtWidgets import QApplication, QFileDialog
import os

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(parent=MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label = QtWidgets.QLabel(parent=self.centralwidget)
        self.label.setGeometry(QtCore.QRect(70, 80, 631, 401))
        self.label.setText("")
        self.label.setObjectName("label")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(parent=MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
        self.menubar.setObjectName("menubar")
        self.menufile = QtWidgets.QMenu(parent=self.menubar)
        self.menufile.setObjectName("menufile")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(parent=MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.actionopen = QtGui.QAction(parent=MainWindow)
        self.actionopen.setObjectName("actionopen")
        self.menufile.addAction(self.actionopen)
        self.menubar.addAction(self.menufile.menuAction())
        self.actionopen.triggered.connect(self.getFileNames())

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.menufile.setTitle(_translate("MainWindow", "file"))
        self.actionopen.setText(_translate("MainWindow", "open"))

    def getFileNames(self):
        file_filter = 'Data File (Image File (*.png *.jpg *jpeg)'
        response = QFileDialog.getOpenFileNames(
            parent=self.centralwidget,
            caption='Select file(s)',
            directory=os.getcwd(),
            filter=file_filter,
            initialFilter='Image File (*.png *.jpg)'
        )
        print(str(response))
if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec())