In what way do you mean you "can't see the captcha info"? Maybe the captcha information is not directly in the HTML but loaded via Javascript or an iframe element. You will have to look at the page source to find out.

As a captcha is usually applied to prevent automation it is also very likely that the captcha server does not respond to naive Perl scripts. Maybe you need to convert your Perl script to behave more like a browser. See for example Wireshark or LWP::Debug how to find out what your browser sends and what LWP sends. Also see WWW::Mechanize to make behaving like a browser easier.