Mailchimp API

mailchimp-dz.php

<?php

$MailChimp = new MailChimp('insert api key here');
$list_id = 'gmj87s22'; // Mailchimp List Id

$email = $_POST['email'];
$first_name = $_POST['firstName'];
$last_name = $_POST['lastName'];

$result = $MailChimp->post("lists/$list_id/members", [
  'email_address' => $email,
  'merge_fields' => [
	'FNAME' => $first_name, 
	'LNAME' => $last_name
  ],
  'status' => 'subscribed'
]);

if ($MailChimp->success()) {
  echo 'Thanks for signing up. Your submittal was successful.';
} else {
  echo 'Something went wrong. You may already be subscribed.';
}