use WWW::Mechanize;
my $mech = WWW::Mechanize->new();
$mech->proxy(['http', 'https'], 'http://xx.xx.x.xx:xx');
print $mech->get("https://example.com");

##</code><code>##

use LWP::UserAgent;
$ua = LWP::UserAgent->new;
$ua->proxy(['http', 'https'], 'http://xx.xx.x.xx:xx');
print $ua->get("https://example.com");