you could use code like that below.

use Net::Telnet::Cisco;
use strict

my $host = '192.168.1.2';
my ($user,$pass,$enable_pass) = 
     qw(username password enable_password);
my $tftp_server = "192.168.1.101";
my $config_file = "switch-confg";
my $dest_file = "startup-config";

my $sess =  Net::Telnet::Cisco->new(Host => '192.168.1.2');
$sess->login($user,$pass);
$sess->enable($enable_pass);

my @out = $sess->cmd("copy tftp start\n$tftp_server\n$config_file\n$de
+st_file\n");
print @out;
@out = $session->cmd("reload\n\n");
print @out;
$sess->close;
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