Help my button event is not working

[JohnnyAidoo]

import kivy

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout

class layout(FloatLayout):
def init (self, **kwargs):
super(). init(**kwargs)

    b1 = Button(
    text = 'press me',
    pos_hint ={'x': 0.2 , 'y': 0.1},
    size_hint = (0.2, 0.1),
    )
    b1.bind(on_pressed =self.pressed)
    
    
    l1= Label(
    text = 'i am a label',
    color =(1,0,0,1)
    )
    self.add_widget(b1)
    self.add_widget(l1)
    
    
        
def pressed(self, elem):
    b1.text ='hiiiii'

class myApp(App):
def build(self):
return layout()

myApp().run()