Botón Kivy Desactivar

def build(self):
        # use a (r, g, b, a) tuple
        btn = Button(text ="Push Me !",
                     font_size ="20sp",
                     background_color =(1, 4, 6, 1),
                     color =(1, 1, 1, 1),
                     size =(32, 32),
                     size_hint =(.2, .2),
                     pos =(300, 250),
  
                     # Disabling the button   
                     disabled = True
  
                     )
My_Life_For_Aiur