API endpoint doesn't work with flet.fastapi.app

[Katsiuk]

Question

Can you explain to me why the following endpoint doesn't work with flet.fastapi.app? I can't get the requirements.txt file.
With a simple FastAPI() it works fine. I didn't receive any messages, but I can't get the file or download.

To start the app, I use the following command: uvicorn --host 0.0.0.0 --port 8000 main:app --reload
Try to go using the following url: http://127.0.0.1:8000/download/requirements.txt
First with this: app = flet_fastapi.app(main, upload_dir="uploads", upload_endpoint_path="uploads", session_timeout_seconds=10)
And then the same url with this: app = FastAPI()
Please help me? I can't understand why it doesn't work.
I am using Flet 0.24.1.
Sending you a full example.
example.zip
Screenshots:

With app = FastAPI()

With app = flet_fastapi.app(main, upload_dir="uploads", upload_endpoint_path="uploads", session_timeout_seconds=10)

Code sample

import flet as ft
import flet.fastapi as flet_fastapi
from fastapi import FastAPI, Response
from fastapi.responses import FileResponse
import os

async def main(page: ft.Page):

    page.add(
        ft.ElevatedButton("Download myfile", on_click=lambda _: page.launch_url("/download/requirements.txt"))
    )


app = flet_fastapi.app(main, upload_dir="uploads", upload_endpoint_path="uploads", session_timeout_seconds=10) # This doesn't work.

# app = FastAPI() # This option works.

def prepare_file(filename: str) -> str:
    return os.path.join("uploads", filename)

@app.get("/download/{filename}")
async def download(filename: str):
    file_path = prepare_file(filename=filename)
    if os.path.exists(file_path):
        return FileResponse(file_path)
    else:
        return {"error": "File not found"}

Error message

No errors.

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• I have searched for answers to my question both in the issues and in previous discussions.