How to make it so that when the button is clicked, the Label changes in Python kivy urgently?

Question

Python

from kivy.app import App

from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.boxlayout import BoxLayout

class myApp(App):
             def build(self):
            bl = BoxLayout(padding=[200, 100], spacing=30)
            gl = BoxLayout(orientation = "vertical")

            gl.add_widget(Label(text = 'привет ты мальчик?', font_size = 50))
            bl.add_widget(Button(text = 'да', font_size = 30,
                                background_color = [.32,.85,.94,1]))

            bl.add_widget(Button(text = 'нет', font_size = 30,
                                 background_color = [1 ,0 ,0, 1]))
       

            gl.add_widget( bl)
            return gl
         


    
if __name__ =="__main__":
   myApp().run()

Answer 1

#-*- coding: utf-8 -*-

from kivy.app import App

from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.boxlayout import BoxLayout

class myApp(App):
    
    def build(self):
        
        gl = BoxLayout(orientation = "vertical", padding=[200, 100], spacing=30)
        self.lbl = Label(text = 'привет ты мальчик?', font_size = 50)
        gl.add_widget(self.lbl)
        gl.add_widget(Button(text = 'да', font_size = 30, background_color = [.32,.85,.94,1], on_press=self.update_label))
        gl.add_widget(Button(text = 'нет', font_size = 30, background_color = [1 ,0 ,0, 1]))
        
        return gl
    
    def update_label(self, instance):
        self.lbl.text = "Привет МАЛЬЧИК"



    
if __name__ =="__main__":
   myApp().run()