Getting error trying to download a subreddit

[Goldmaster]

Hi there, I am trying out your archiving to download a subreddit, but for some reason im getting this error message in Windows 10 bash.

I type in
python3 subreddit.py subreddit and have tried just typing python and that doesn't work either, and I am getting

Traceback (most recent call last): File "/mnt/c/Users/username/Downloads/Compressed/redditPostArchiver-master/subreddit.py", line 13, in <module> from simplejson.scanner import JSONDecodeError ModuleNotFoundError: No module named 'simplejson'.

Any reason why? I have followed the readme though and set up fine.