bug: AttributeError: module 'flet.controls.cupertino.cupertino_icons' has no attribute 'ADD'

[icstos]

Duplicate Check

• I have searched the opened issues and there are no duplicates

Describe the bug

In the code of the official document, the error is reported when running

Code sample

https://flet.dev/docs/cookbook/adaptive-apps

Code

import flet as ft

def main(page):

    page.adaptive = True

    page.appbar = ft.AppBar(
        leading=ft.TextButton("New", style=ft.ButtonStyle(padding=0)),
        title=ft.Text("Adaptive AppBar"),
        actions=[
            ft.IconButton(ft.cupertino_icons.ADD, style=ft.ButtonStyle(padding=0))
        ],
        bgcolor=ft.Colors.with_opacity(0.04, ft.CupertinoColors.SYSTEM_BACKGROUND),
    )

    page.navigation_bar = ft.NavigationBar(
        destinations=[
            ft.NavigationBarDestination(icon=ft.Icons.EXPLORE, label="Explore"),
            ft.NavigationBarDestination(icon=ft.Icons.COMMUTE, label="Commute"),
            ft.NavigationBarDestination(
                icon=ft.Icons.BOOKMARK_BORDER,
                selected_icon=ft.Icons.BOOKMARK,
                label="Bookmark",
            ),
        ],
        border=ft.Border(
            top=ft.BorderSide(color=ft.CupertinoColors.SYSTEM_GREY2, width=0)
        ),
    )

    page.add(
        ft.SafeArea(
            ft.Column(
                [
                    ft.Checkbox(value=False, label="Dark Mode"),
                    ft.Text("First field:"),
                    ft.TextField(keyboard_type=ft.KeyboardType.TEXT),
                    ft.Text("Second field:"),
                    ft.TextField(keyboard_type=ft.KeyboardType.TEXT),
                    ft.Switch(label="A switch"),
                    ft.FilledButton(content=ft.Text("Adaptive button")),
                    ft.Text("Text line 1"),
                    ft.Text("Text line 2"),
                    ft.Text("Text line 3"),
                ]
            )
        )
    )

ft.run(main)

To reproduce

Steps to reproduce: Run the repro code

Expected behavior

No response

Screenshots / Videos

Captures

[Upload media here]

Operating System

Windows

Operating system details

Windows11

Flet version

0.85.1

Regression

I'm not sure / I don't know

Suggestions

No response

Logs

Logs

[Paste your logs here]

Additional details

No response