Hi Nate,
Thanks for the heads-up in the broken link. I've updated it with one from the web archive.
You can run the following command to try find the apache2 location
whereis apache2
https://www.howtogeek.com/devops/how-to-find-your-apache-configuration-folder/
It sounds like your Dockerfile or container is using a different set up, it really depends on what docker image you're using or if you're using a custom one. File locations might change from docker image to docker image.
Maybe those directories are in a different location in yours.
Other common locations are:
/etc/apache2/conf/httpd.conf
/usr/local/apache2/conf/httpd.conf
/usr/local/etc/httpd/httpd.conf
For example, the HTTPD Docker image has some instructions of how to change the config file.
https://hub.docker.com/_/httpd
Hope this helps!