pyqt5 problem. I am having trouble with classes. When I call the function it doesn't do anything at all

Question

##imports

from PyQt5.QtWidgets import (QWidget, QPushButton, QLineEdit, QInputDialog, QApplication, QLabel,QMainWindow,)
from PyQt5.QtWidgets import QLineEdit 
from PyQt5.QtGui import *
import sys

#defining class

class UI:
    

#basic window

    def window(self,app,window,size,title,show,):
        self.app = QApplication(sys.argv)
        self.win = QMainWindow()
        self.win.setGeometry(200,200,600,600) 
        self.win.setWindowTitle("Calculator App  ") 

        self.win.show()
        sys.exit(app.exec_())

#text that will show the functions of the calculator

    def modes_header(self,type,text,pos,font):
        self.functions_type = QLabel(win)
        self.functions_text.setText("Modes")
        self.functions_pos.move(10, 400)
        self.functions_font.setFont(QFont('Constantinus',21))

#this will be the multiplication function

    def multiply_button(self,label,text,pos,font):
        self.multButton_type = QLabel(win)
        self.multButton_text.setText("Multiply")
        self.multButton_pos.move(10,450)
        self.multButton_font("Arial",19)

#Calling Functions

ui = UI
win = ui.window

ui.window()
ui.modes_header()
ui.multiply_button()