icingaweb2/modules/setup/application/views/scripts/form/setup-requirements.phtml

<?php

use \RecursiveIteratorIterator;
use Icinga\Web\Wizard;

$requirements = $form->getRequirements();
$iterator = new RecursiveIteratorIterator($requirements);

?>
<table class="requirements">
  <tbody>
<?php foreach ($iterator as $requirement): ?>
    <tr>
      <td><h2><?= $requirement->getTitle(); ?></h2></td>
      <td style="width: 50%">
      <?php $descriptions = $requirement->getDescriptions(); ?>
      <?php if (count($descriptions) > 1): ?>
        <ul>
        <?php foreach ($descriptions as $desc): ?>
          <li><?= $desc; ?></li>
        <?php endforeach ?>
        </ul>
      <?php elseif (! empty($descriptions)): ?>
        <?= $descriptions[0]; ?>
      <?php endif ?>
      </td>
      <td class="state <?= $requirement->getState() ? 'fulfilled' : (
        $requirement->isOptional() ? 'not-available' : 'missing'
      ); ?>"><?= $requirement->getStateText(); ?></td>
    </tr>
<?php endforeach ?>
    <tr>
      <td></td>
      <td></td>
      <td class="btn-update">
        <div class="buttons">
          <?php $title = $this->translate('You may also need to restart the web-server for the changes to take effect!'); ?>
          <?= $this->qlink(
            $this->translate('Refresh'),
            null,
            null,
            array(
              'class'       => 'button-like',
              'title'       => $title,
              'aria-label'  => sprintf($this->translate('Refresh the page; %s'), $title)
            )
          ); ?>
        </div>
      </td>
    </tr>
  </tbody>
</table>
<form id="<?= $form->getName(); ?>" name="<?= $form->getName(); ?>" enctype="<?= $form->getEncType(); ?>" method="<?= $form->getMethod(); ?>" action="<?= $form->getAction(); ?>">
  <?= $form->getElement($form->getTokenElementName()); ?>
  <?= $form->getElement($form->getUidElementName()); ?>
  <div class="buttons" style="margin: 0 0 1.5em;">
    <?= $form->getElement(Wizard::BTN_PREV); ?>
    <?php
      $btn = $form->getElement(Wizard::BTN_NEXT);
      if (false === $requirements->fulfilled()) {
          $btn->setAttrib('disabled', 1);
      }
      echo $btn;
    ?>
  </div>
</form>