$password = "";
$codeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
$codeAlphabet .= "abcdefghijklmnopqrstuvwxyz";
$codeAlphabet .= "!@#$";
$codeAlphabet .= "0123456789";
$max = strlen($codeAlphabet); // edited
for ($i = 0; $i < 12; $i++) {
$password .= $codeAlphabet[rand(0, $max - 1)];
}

//Here we are storing the user data in wp
$userData = array('user_login' => $email, 'user_pass' => $password, 'user_email' => $email, 'role' => 'subscriber');
$userId = wp_insert_user($userData);

// DEBUG:
​$contact_id = get_user_meta( $userId, 'ontraport_contact_id', true );
​wpf_log( 'notice', $userId, 'DEBUG: Contact ID is ' . $contact_id );

wp_new_user_notification( $userId, null, 'user', $password);

$subscriber_tag_id = 8;

$tags = array($subscriber_tag_id);

if (isset($_REQUEST['newsletter'])) {
//$newsletter_tag_id = wp_fusion()->user->get_tag_id('newsletter');
$newsletter_tag_id = 7;
array_push($tags, $newsletter_tag_id);
}
//this is adding iscrittoFNOPI tag when fnopi is validate
if($cf_check == 1) {
$cf_fnopi_id = wp_fusion()->user->get_tag_id('iscrittoFNOPI');
array_push($tags, $cf_fnopi_id);
}

wp_cache_delete( $userId, 'users' );

wp_fusion()->user->apply_tags($tags, $userId);