https://github.com/flet-dev/website/blob/main/docs/tutorials/trello-clone.md
I think app_layout.py is missing:
from flet.core.control import Control
due to the line
self._active_view: Control = ft.Column(
Also, Sidebar.py contains the line:
def __init__(self, app_layout, store: DataStore):
I've no clue what DataStore is?