you should check your errors / log files for prior problems and provide more info.

My guess is you either haven't installed all necessary files or your path settings are wrong, such that the "elsewhere" available code defining the function main::param() is never imported/required/executed.

update

on a side note: using apache for that sounds like overkill, many apps allow bundling a built-in webserver. Like some build with the Mojolicious framework.