test.py

from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.button import Button
from kivy.app import App


class TestApp(App):

    def build(self):
        layout = AnchorLayout(anchor_x="right", anchor_y="bottom")
        btn = Button(text="Hello World", size_hint=(None, None))
        layout.add_widget(btn)
        return layout


if __name__ == "__main__":
    TestApp().run()