User field zeigt keine Funktion

<?xml version="1.0" encoding="utf-8"?>
<form addfieldpath="/administrator/components/com_jugendplaner/models/fields">
    <fieldset name="jugendplanerapikey_edit">
        <field
                name="id"
                type="hidden"
                />
        <field
                name="userid"
                type="user"
                label="COM_JUGENDPLANER_JUGENDPLANER_API_USER_LABEL"
                description="COM_JUGENDPLANER_JUGENDPLANER_API_USER_DESC"
                required="true"
                message="Wähle einen User aus."
                />
        <field
                name="key" label="Key"
                type="text"
                readonly="true"
                />
        <field
                name="neuerkey" type="checkbox"
                label="Key erneuern"
                showon="key!:"
                value="1"
                />
    </fieldset>
</form>

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');

class JugendplanerModeljugendplanerapikey extends JModelAdmin
{
    public function getTable($type = 'jugendplanerapikeys', $prefix = 'jugendplanerTable', $config = array())
{
        return JTable::getInstance($type, $prefix, $config);
}

    public function getForm($data = array(), $loadData = true)
{
        // Get the form.
        $form = $this->loadForm(
            'com_jugendplaner.jugendplanerapikey',
            'jugendplanerapikey',
            array(
                'control' => 'jform',
                'load_data' => $loadData
)
);

        if (empty($form))
{
            return false;
}

        return $form;
}

    protected function loadFormData()
{
        // Check the session for previously entered form data.
        $data = JFactory::getApplication()->getUserState(
            'com_jugendplaner.edit.jugendplanerapikey.data',
            array()
);

        if (empty($data))
{
            $data = $this->getItem();
}

        return $data;
}
}

<?php
/**
* @package Joomla.Administrator
* @subpackage com_jugendplaner
*
* @copyright Copyright (C) 2019 Jonas Badstübner
* @license GNU General Public License version 2 or later; see LICENSE.txt
*/

// No direct access
defined('_JEXEC') or die('Restricted access');

?>
<form action="<?php echo JRoute::_('index.php?option=com_jugendplaner&layout=edit&id=' . (int) $this->item->id); ?>"
method="post" name="adminForm" id="adminForm" class="form-validate">
<div class="form-horizontal">
<fieldset class="adminform">
<legend><?php echo JText::_('COM_JUGENDPLANER_JUGENDPLANER_API_KEY_DETAILS'); ?></legend>
<div class="row-fluid">
<div class="span6">
<h6 style="color: #ff0000;"><?php echo JText::_('COM_JUGENDPLANER_JUGENDPLANER_API_KEY_WARNING'); ?></h6>
<?php echo $this->form->renderFieldset('jugendplanerapikey_edit'); ?>
</div>
</div>
</fieldset>
</div>
<input type="hidden" name="task" value="jugendplanerapikey.edit" />
<?php echo JHtml::_('form.token'); ?>
</form>