Why is Heroku failing to compile my python application?

I've downloaded this module called guesslang through pip and I've added it to my requirements.txt file for Heroku to download it. When I run my discord bot locally, it works with no issues. However, whenever I deploy it on Heroku, I get this error:

ERROR: Could not find a version that satisfies the requirement tensorflow==2.2.0 (from guesslang==2.0.1->-r /tmp/build_ca38c743_/requirements.txt (line 11)) (from versions: none)
       ERROR: No matching distribution found for tensorflow==2.2.0 (from guesslang==2.0.1->-r /tmp/build_ca38c743_/requirements.txt (line 11))
 !     Push rejected, failed to compile Python app.
 !     Push failed

Here's my requirements.txt file:

git+https://github.com/Rapptz/discord.py
PyNaCl==1.3.0
dnspython==1.16.0
pandas
async-timeout==3.0.1
pip
youtube_dl
colorlog
pyjokes
howdoi
guesslang

How can I fix this?

from Why is Heroku failing to compile my python application?