Why my pop up window in not appearing in python using kivy?

I’m still new to python and I’m trying to learn how to use kivy but when I was just trying it there’s no pop-up window that comes out as it should or as I saw from the videos I follow, Please, help. Thank you.

import kivy
from kivy.app import App
from kivy.uix.label import Label

class MyApp(App):
    def build(self):
        return Label(text = "Hi! How are you?")

if __name__ == " main ":
    MyApp().run()

>Solution :

Have you tried this instead?

class MyApp(App):

def build(self):
    return Label(text='Hello world')

if __name__ == '__main__':
    MyApp().run()

More examples on the kivy documentation site: https://kivy.org/doc/stable/guide/basic.html