Problems accessing content in www folder

I am trying to serve an HTML file (index.html) which I have placed in my config/www folder. When I try to access it using the URL below I get a 404 error:

https://mydomain.ddns.net:8123/local/index.html

I can access the Lovelace GUI using this URL without any problems:

https://mydomain.ddns.net:8123

I’m running HA Core 2021.12.7 in a Docker container. I have set all permissions on both the www folder and its contents to “anyone”.
Any idea why I can’t access this file via the URL?

Did you restart home assistant after creating the www folder?

No I hadn’t (thanks), but I have now and I still get this:

Log Text: 404: Not Found

???

Ah…sorry…there was an error in my HTML file…I did in fact manage to access it.
Thanks!