Add welcome ticket in helpdesk when user signup

Add this code to site.php file:

Am_Di::getInstance()->hook->add(Am_Event::SIGNUP_USER_ADDED, function (Am_Event $event) {
    $user = $event->getUser();
    $di = $event->getDi();

    $ticket = $di->helpdeskTicketRecord;
    $ticket->created = $ticket->updated = sqlTime('now');
    $ticket->user_id = $user->user_id;
    $ticket->status = HelpdeskTicket::STATUS_AWAITING_USER_RESPONSE;

    // TICKET SUBJECT
    $ticket->subject = 'Welcome user '.$user->name_f.' '.$user->name_l;
    $ticket->has_new = 1;
    $ticket->insert();

    $message = $di->helpdeskMessageRecord;
    $message->dattm = sqlTime('now');
    $message->admin_id = 1; // ADMIN ID
    $message->type = 'message';
    $message->setAttachments([]);

    // TICKET BODY
    $message->content =  'Welcome to helpdesk. Simple content';
    $message->ticket_id = $ticket->ticket_id;
    $message->insert();
});