Answered ActiveationEmail - display username and fullname in email

$fields = array(
    'username' => $name,
    'sitename' => $siteName,
    'activationURL' => $activeURL,
    'deactivationURL' => $deActiveURL,
);

$fullName = $profile->get('fullname');

$fields = array(
    'fullname' => $fullName,
    'username' => $name,
    'sitename' => $siteName,
    'activationURL' => $activeURL,
    'deactivationURL' => $deActiveURL,
);