PerlModule is equivalent to require. For example:

#!usr/bin/perl

use strict;
use warnings;
require Apache::DBI;
require DBI;
require CGI;
[download]

In your conf:

PerlModule Apache::DBI DBI CGI
[download]

Note that require is for "after" configuration. To use your modules at startup, use PerlLoadModule:

PerlLoadModule Apache::DBI DBI CGI
[download]