Check Box Displays Button

So first I'm assuming I may need to create a separate kv file; however, I'm pretty sure this may do just fine with a py file.

Essentially, I'm trying to create where each column contains pulls a list of from a text file in the label (Checkbox test 1) and checkboxes next to each item. Once all checkboxes are checked, a button will appear to complete and exports the list to a text file and start over. I'm pretty beginnerish with this and I'm sure I'm missing a lot such as a loop and perhaps the kv file and maybe a bit more.

from kivy.uix.checkbox import CheckBox
# Graphics related
from kivy.graphics import InstructionGroup
from kivy.graphics import Color
from kivy.graphics import Rectangle

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.core.window import Window

#read text file here first?

class UserInterface(GridLayout):

def __init__(self, **kwargs):
    super(UserInterface, self).__init__(**kwargs)
    # Add labels and checkbox
    self.rows = 3
    self.cols = 3
    self.add_widget(Label(text='Checkbox Test 1'))
    self.cb_roateMode = CheckBox(active=True)
    self.add_widget(self.cb_roateMode)
    self.lbl_roateMode = Label(text='Checkbox 1 Sync Test')
    self.add_widget(self.lbl_roateMode)

    self.add_widget(Label(text='Checkbox Test 1'))
    self.cb_roateMode = CheckBox(active=True)
    self.add_widget(self.cb_roateMode)
    self.lbl_roateMode = Label(text='Checkbox 1 Sync Test')
    self.add_widget(self.lbl_roateMode)

    self.add_widget(Label(text='Checkbox Test 1'))
    self.cb_roateMode = CheckBox(active=True)
    self.add_widget(self.cb_roateMode)
    self.lbl_roateMode = Label(text='Checkbox 1 Sync Test')
    self.add_widget(self.lbl_roateMode)

    # Change the color of the background to grey
    blue = InstructionGroup()
    blue.add(Color(1, 1, 1, .3))
    blue.add(Rectangle(pos=self.pos, size=(Window.width, Window.height)))
    self.canvas.add(blue)

    #callback
    self.cb_roateMode.bind(active=self.on_roateMode_Active)

# Callback for the checkbox

def on_roateMode_Active(self, checkboxInstance, isActive):
    if isActive:
        self.lbl_roateMode.text = "Checkbox 1 Checks! Create Button"
    else:
        self.lbl_roateMode.text = "Checkbox 1 Unchecks! No Button"

#Button Here?

class CheckBoxApp(App):
def build(self):
    ux = UserInterface()
    return ux


# Run the app

if __name__ == '__main__':
CheckBoxApp().run()

Something like this; however, the layout I'm confident I can do just the functionality is where I'm struggling

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