Что я делаю не так ? В чём моя ошибка ?

from kivy.app import App 
from kivy.uix.button import Button 
from kivy.uix.textinput import TextInput 
from kivy.uix.label import Label
from kivy.uix.popup import Popup
from kivy.uix.widget import Widget
 
from kivy.config import Config
 
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.floatlayout import FloatLayout
 
class p(FloatLayout):
    Label(text = "Слово", size_hint = (.4, .2))
 
class release(Widget):
    def show_popup(self):
        show = p()
 
        popupWindow = Popup(title = "Словарь", content = show, size_hint = (None, None), size = (320, 600))
        popupWindow.open()
 
class MyApp(App):
    def build(self): #создает окно приложения
        bl = BoxLayout(orientation = "vertical", padding = [0, 80, 0, 0], spacing = 2) 
        ti = TextInput(size_hint = (1, .2), font_size = 30, multiline = False)
 
        bl.add_widget(ti)
        bl.add_widget(Button(text = "Словарь", font_size = 30, background_color = [0, .6, .6, 1], background_normal = "", on_release = release.show_popup()))
        bl.add_widget(Button(text = "Добавить слово", font_size = 30, background_color = [0, .6, .6, 1], background_normal = ""))
 
 
        return bl
 
 
if __name__ == '__main__':
    MyApp().run()