Just example...

com-builder-get-user-fields.php

<?php
if (file_exists( JPATH_ADMINISTRATOR . '/components/com_comprofiler/plugin.foundation.php' ) ) {
    include_once( JPATH_ADMINISTRATOR . '/components/com_comprofiler/plugin.foundation.php' );
    
    if (class_exists('CBuser')) {
        $user = JFactory::getUser();
        if ($user && $user->id) {
            $cbUser = CBuser::getInstance($user->id);
            $user = $cbUser->getUserData();
            dump($cbUser, 0);
            dump($user, 0);
            dump($user->lastname, 0);
        }
    }    
}