use WWW::Mechanize;
use Data::Dumper;
use Crypt::SSLeay;

my $mech = WWW::Mechanize->new();

$mech->get( 'https://www.zentrada.de/login/' );
$mech->submit_form(
    form_number => 2,
    fields      => {
        'ff_email'    => 'xxx@gmx.de',
        'ff_passwort' => 'asdf!&§',
    },
);

if ($response->is_success) {
        print $response->decoded_content;
}
else {
        print STDERR $response->status_line, "\n";
}