Maybe this is it:

 ref EXPR
 ref          Returns a non‐empty string if EXPR is a reference

You wrote this:

if ( ref $address eq HASH )

HASH doesn't look like a string to me. Here is a proof of concept:

use strict;
use warnings;
use 5.010;


my %h1 = qw{Addressee David Street Street1};
my %h2 = qw{Addressee Kathy Street Street2};
my $templist;

#my $address = [\%h1, \%h2];
my $address = \%h1;

if (ref $address eq 'HASH') {
    $templist = [$address];
}else{
    $templist = $address;
}

foreach  my $response ( @ $templist  ) {
    print "name: $response->{Addressee}<br>\n";
    print "street: $response->{Street}<br>\n";
}

--output:--
name: David<br>
street: Street1<br>
[download]

You can toggle the comment to see that the code works for a reference to an array of hashes, as well as a reference to a hash.