You need to read the Net::Telnet documentation, and do, at least, a small configuration of the module.

$telnet = new Net::Telnet(timeout => 10,
                                         # do not you the 'return'
                                         Errmode => 'die',
                                         # change the prompt
                                         Prompt => '/ </$'); # I'm gue
+ssing this prompt ' <'
$telnet->input_log($log_file);
$telnet->dump_log($dump_file);
$telnet->waitfor( -match => qr{ENTER USERNAME}  );
$telnet->print($username);
$telnet->waitfor( -match => qr{ENTER PASSWORD}  );
$telnet->print($passard);
#
# and finally send a command
@lines = $t->cmd("who");
for (@lines) { print }
[download]