Kivymd graphic gui interface ,next page,add paragraph

from kivymd.app import MDApp
from kivymd.uix.screen import Screen
from kivy.lang import Builder

kv = '''
<MyScreen>:
  MDLabel:
      text: "yo"
      pos_hint: {"center_x": .5, "center_y": .5}
'''

Builder.load_string(kv)

class MyScreen(Screen):
  pass

class MyApp(MDApp):
  def build(self):
    return MyScreen()
MyApp().run()