我在将python应用程序部署到heroku时遇到了这个错误，这让我抓狂

Question

我在尝试将python应用程序部署到heroku时遇到了这个错误。 我已经安装了Python3.8.2，它可用于堆栈

（venvm）C:\Users\xxxx\pycharm项目\watstwillio>；git推送heroku主机

> Enumerating objects: 3284, done. Counting objects: 100% (3284/3284),
> done. Delta compression using up to 4 threads Compressing objects:
> 100% (3250/3250), done. Writing objects: 100% (3284/3284), 19.41 MiB |
> 942.00 KiB/s, done. Total 3284 (delta 916), reused 0 (delta 0) remote: Compressing source files... done. remote: Building source: remote:
> remote: -----> Python app detected remote:  !     Requested runtime
> (python-3.8) is not available for this stack (heroku-18). remote:  !  
> Aborting.  More info:
> https://devcenter.heroku.com/articles/python-support remote:  !    
> Push rejected, failed to compile Python app. remote: remote:  !    
> Push failed remote: Verifying deploy... remote: remote: !       Push
> rejected to whatsapbot. remote: To
> https://git.heroku.com/whatsapbot.git  ! [remote rejected] master ->
> master (pre-receive hook declined) error: failed to push some refs to
> 'https://git.heroku.com/whatsapbot.git'

My requirements.txt看起来像：

certifi==2019.11.28
chardet==3.0.4
Click==7.0
Flask==1.1.1
gunicorn==20.0.4
idna==2.9
itsdangerous==1.1.0
Jinja2==2.11.1
MarkupSafe==1.1.1
PyJWT==1.7.1
pytz==2019.3
requests==2.23.0
six==1.14.0
twilio==6.35.5
urllib3==1.25.8
Werkzeug==1.0.0

runtime.txt如下所示：

python-3.8.2

我还注意到，这个错误没有提到我安装的python的完整版本，它说：“请求的运行时（python-3.8）”

我尝试重新安装python，但没有效果。我做错了什么？请帮忙