Issue with import Flask in app.py

[kwiatks]

convert-video-to-audio git:(master) ✗ docker --version
Docker version 20.10.7, build f0df350
git clone https://github.com/IBM/convert-video-to-audio

cd convert-video-to-audio

docker image build -t convert-video-to-audio .
(build ran successfully)

➜ convert-video-to-audio git:(master) ✗ docker run -p 8080:8080 convert-video-to-audio
Traceback (most recent call last):
File "app.py", line 1, in
from flask import Flask, render_template, request, redirect, jsonify
File "/usr/local/lib/python3.5/dist-packages/flask/init.py", line 14, in
from jinja2 import escape
File "/usr/local/lib/python3.5/dist-packages/jinja2/init.py", line 5, in
from .bccache import BytecodeCache as BytecodeCache
File "/usr/local/lib/python3.5/dist-packages/jinja2/bccache.py", line 61
self.code: t.Optional[CodeType] = None
^
SyntaxError: invalid syntax

[kwiatks]

Took out all versions from requirements.txt

Flask
Flask-Cors
werkzeug
ibm-cos-sdk
ffmpeg-python

Change one line in app.py
from werkzeug.utils import secure_filename

Then app worked as required and could successfully start the app and complete uploads and extract audio from video and do Step 3 -> Play the Audio file(s) from Cloud Object Storage