Rename a url with .htaccess for a website page

I am trying to rename a url from www.mywebsite.com/insights/ to www.mywebsite.com/insights/new-link

This isn't a new directory I am wanting to point towards, it's the exact same page, but I want to give it a new url name.

I think I have to use .htaccess, and I've looked at the other threads here and they say to write something like this in my .htaccess file:

RewriteEngine On
RewriteRule ^en/insights/$ /en/insights/test [L] 

Nothing happens, and it doesn't even look like that code is registering in the .htaccess file (I've never create a .htaccess file before, but the code isn't colour coded like in .html, .css or .js, which is leading me to think it's not even registering)

I'm not using any web framework, all my files are just plain .html .css and .js, but I do have a python build.py file to build the website (not my choosing, this code was inherited and its what my company has done to get it on our database). I believe this section in the build.py file build the different pages, so maybe I also have to add something here?

prod = False
pages = ['homepage', 'solutions', 'work', 'shipmentTracking', 'insights']
srcLoc = 'src'
assetsLoc = 'assets'
buildLoc = 'dist/build'

Or do I need to import something into the buily.py file, in order for .htaccess to work? I'm very new at this, any help would be greatly appreciated!