How would i add a widget to a StackLayout inside a ScrollView inside a FloatLayout?

Question

Fairly new to kivy and only have a highschool education of python and have been stuck on this for a week now. I want a system where i can add and remove buttons in the StackLayout, how would i go about doing that?

I can add and remove the buttons I now just need to figure out how to place them in the correct area.

I understand this question is a bit of a clusterf*** and i have jumped in the deep end with this but i figured best was to learn is to dive right in to it.

pythton code:

# import kivy & functions/widgets.
import kivy
from kivy.app import App
from kivy.uix.button import Button

# import kivy layouts.
from kivy.uix.floatlayout import FloatLayout

# Specify version of kivy needed.
kivy.require("1.10.1")

# define buttons and widgets
testButton = Button(width=177, height=254, size_hint=(None, None), background_normal="pics/32864.jpg")


class Page(FloatLayout):
    def __init__(self):
        super().__init__()

    def add_button(self):
        Page.add_widget(self, widget=testButton)


class YuGiOhApp(App):
    pass


YuGiOhApp().run()

My .kv code:

#:kivy 1.10.1

<[email protected]>:
    width: 177
    height: 254
    size_hint: None, None
    background_normal: "pics/32864.jpg"

FloatLayout:

    Button:
        size_hint: 0.20, 0.10
        pos_hint: {"x": 0.60, "top": 1}
        text: "Search"
        on_press: root.add_button()

    Button:
        size_hint: 0.20, 0.10
        pos_hint: {"x": 0.80, "top": 1}
        text: "collection"

    TextInput:
        multiline: False
        font_size: 48
        size_hint: 0.60, 0.10
        pos_hint: {"x": 0, "top": 1}

    ScrollView:
        size_hint: 0.60, 0.90

        StackLayout:
            orientation: "lr-tb"
            pos_hint: {"x": 0, "top": 0.88}
            size_hint: 1, None

            height: self.minimum_height

            padding: 5
            spacing: 5

            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:
            TestButton:

Edit 4: Getting the error "AttributeError: 'FloatLayout' object has no attribute 'add_button'" when trying to run the add_button() function when the button labeled "search" is pressed