This is really a Javascript question. Presumably you would call Perl code in the same way you would call any other external application or script, whether it's a shell script, Python, a compiled binary, or what have you. I would ask a Javascript guru how to do this. My knowledge of Javascript can safely be described as "limited".

We could tell you how to use Javascript code from within a Perl application... but that's the reverse of what you want to do.