R Shiny - use page instead of port

I've followed the directions here and here to get a Shiny hello world app running on my webserver but I can only access it via my homepage then a port number. For example, R shows Listening on http://0.0.0.0:6548 and I need to type in myHostName.org:6548 and I can see my app.

If I want to turn this into myHostName.org/app1 instead, how can I do this?