It used to be possible to have an Apache interface directly with the ASP.NET engine / system via mod_aspdotnet, but this module was left some time ago.
Now you must make Apache a front-end server (port 80) and have IIS for the internal server (8080). Then use the Apache ProxyPass directive for proxy sites or URLs for IIS that runs the ASP.NET code and returns the Apache result that delivers it to the visitor / client.
This is not a bad option and works well.
You just need to make sure that you are running Apache and IIS on different IP addresses or on the same IP address, but on different ports.