use LWP::UserAgent ();
use LWP::Protocol::https;

my $url = 'https://example.org/SOAP/opera/4711';

my $ua = LWP::UserAgent->new;
my $content = 'TEST';

$ua->ssl_opts(
    SSL_ca_file   => 'cacert.pem',
    SSL_cert_file => 'clientcert.pem',
);

$ua->post(
    $url,
    Content => $content,
);