If anyone else is a dumb as me, here's the solution.

#!/usr/bin/perl

use CGI qw/:standard/;
use strict;
use warnings;

$user='user1';

$cookie1 = cookie(-name=>'user',
          -value=>"$user",
          -expires=>'+1h');
          -path => '/', 
     print header(-cookie=>$cookie1);
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