$hmac_key = 'your hmac key';
$hmac_secret = 'your secret';
$search = array('.');
$replace= array('');
$mt = microtime(true);
$mt = str_replace($search,$replace,$mt);
$nonce = $mt;
$api_endpoint = '/api/myself/';
$url = 'https://localbitcoins.com'.$api_endpoint;
$get_or_post_params_urlencoded = '';
$message = $nonce . $hmac_key . $api_endpoint . $get_or_post_params_urlencoded;
$message_bytes = utf8_encode($message);
$signature = mb_strtoupper( hash_hmac( 'sha256', $message_bytes, $hmac_secret ) );
$ch = curl_init('https://localbitcoins.com'.$api_endpoint);
$options = array(
CURLOPT_RETURNTRANSFER => 1,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTPHEADER =>   array(
'Apiauth-Key:'.$hmac_key,
'Apiauth-Nonce:'.$nonce,
'Apiauth-Signature:'.$signature
),
);
curl_setopt_array($ch, $options);
$result = curl_exec($ch);
curl_close($ch);
echo $result;


##</code><code>##

#!/usr/bin/perl -w

BEGIN {
    print "Content-type: text/plain\n\n";
}


use LWP::UserAgent;
use Time::HiRes qw(gettimeofday);
use Digest::SHA qw(sha256);
use URI;
use URI::QueryParam;
use CGI::Carp qw(fatalsToBrowser);


my $uri = URI->new();

my $nonce = int (gettimeofday * 1000);

$url = "https://localbitcoins.com";
$api_endpoint = "/api/merchant/new_invoice/";
$hmac_key = "sfsdfdsfdsfsdf";
$hmac_secret = "fsdfdsfdsfd";

%params = (
    currency         => 'USD', 
    amount           => '500', 
    description      => 'HEY', 
    internal         =>  '0',   
);

$uri->query_param($_, $params{$_}) for keys %params;
$post_params_urlencoded = $uri->query;

$message = ($nonce.$hmac_key.$api_endpoint.$post_params_urlencoded);
my $signature =  unpack("H*", sha256($message, $hmac_secret));

my $ua = LWP::UserAgent->new;
my $res = $ua->post(
     $url.$api_endpoint,
    "Apiauth-Key" => "$hmac_key",
	"Apiauth-Nonce" => "$nonce",
    "Apiauth-Signature" => "$signature", 
);


if ($res->is_success) {
    print $res->content;
} 
else {
print $res->status_line, "\n";
}