run a proxy server in frontThere is only one reference to the word "proxy" in the installation instructions.
to the configuration. For example, on one of my machines (running Oracle Enterprise Linux with OEL's Apache), I put these lines in /etc/httpd/conf.d/apex.conf. After a restart of Apache, it serves /i/ directly and passes all requests to /apex/... on to http://127.0.0.1:8888/apex/... In that configuration, Apex Listener standalone has to listen on port 8888 on the same machine (127.0.0.1, or localhost). You will have to consult /etc/httpd/conf/httpd.conf to find the port where Apache listens (e.g. "Listen 8080") and maybe modify it, to avoid server port clashes.
Alias /i/ /path/to/apex/images/ <Location /apex/> ProxyPass http://127.0.0.1:8888/apex/ ProxyPassReverse http://127.0.0.1:8888/apex/ </Location>