Oh. That’s a whole other thing, and quite do-able. Search results for 'discourse apache' - Discourse Meta has a bunch of topics.
Oh, then I’ve been answering the wrong question. 
For $1500 I’ll install as many Discourse and Wordpress and Ghost sites as you want on a single server with traefik on the front end doing https. You can even have Discourse in a sub-folder (which I really don’t recommend, but a client wants it so I’ve got that scripted.
But the search above links to a couple howto documents that should get you where you need to be for free.