Hello,I clone the repository and installed the requirement.txt,but also have some questions

[xinoer]

The question when I run server.py , the Pycharm or VScode told me
FLASK_APP = server.py
FLASK_ENV = development
FLASK_DEBUG = 0
In folder /home/zhao/PycharmProjects/flask_webrtc_youtube-master
/home/zhao/PycharmProjects/flask_webrtc_youtube-master/.venv/bin/python -m flask run
Usage: python -m flask run [OPTIONS]
Try 'python -m flask run --help' for help.

Error: While importing 'server', an ImportError was raised:

Traceback (most recent call last):
File "/home/zhao/PycharmProjects/flask_webrtc_youtube-master/.venv/lib/python3.8/site-packages/flask/cli.py", line 247, in locate_app
import(module_name)
File "/home/zhao/PycharmProjects/flask_webrtc_youtube-master/server.py", line 2, in
from flask_socketio import SocketIO, emit, join_room
File "/home/zhao/PycharmProjects/flask_webrtc_youtube-master/.venv/lib/python3.8/site-packages/flask_socketio/init.py", line 19, in
from flask import _request_ctx_stack, has_request_context, json as flask_json
ImportError: cannot import name '_request_ctx_stack' from 'flask' (/home/zhao/PycharmProjects/flask_webrtc_youtube-master/.venv/lib/python3.8/site-packages/flask/init.py)

perhaps flask cause this question,but the requirement.txt don't rugulation flask version.