Is there a way to redirect a non-www subdirectory to that subdirectory with the www domain?

Question

I'm new to web hosting and I'm currently having trouble redirecting subdirectories that don't have the www subdomain.

Typing

example.com/subdirectory/ 

just goes to

https://www.example.com/

I want it to go to from

example.com/subdirectory/ 

to

https://www.example.com/subdirectory/

I'm using django, pythonanywhere, and namecheap.

I've already looked a lot online but there just doesn't seem to be any examples with someone using django, pythonanywhere and namecheap. There were some cases where using htaccess solved the problem, but I don't think it's compatible with django?