Having trouble getting redirect to work

You’d want a rewrite then, not a redirect. A redirect is telling the browser to make a new request at a URL, by responding with the Location header in the response.

You probably want this:

jump.systems.dance {
  rewrite * /guacamole{path}
  reverse_proxy http://192.168.1.60:8081 {
    flush_interval -1
  }
}

But be aware that you may run into issues if guacamole is not aware of this: