icingaweb2/modules/monitoring/application/views/scripts/show/components/actions.phtml

<?php
use Icinga\Module\Monitoring\Object\MonitoredObject;

// add warning to links that open in new tabs to improve accessibility, as recommended by WCAG20 G201
$newTabInfo = sprintf('<span class="info-box display-on-hover"> %s </span>', $this->translate('opens in new window'));

$links = MonitoredObject::parseAttributeUrls($object->action_url);
foreach ($links as $i => $link) {
    $links[$i] = sprintf(
        '<a href="%s" target="_blank">%s ' . $newTabInfo . '</a>',
        $this->resolveMacros($object->action_url, $object),
        'Action'
    );
}

if (isset($this->actions)) {
    foreach ($this->actions as $id => $action) {
        $links[] = sprintf('<a href="%s">%s</a>', $action, $id);
    }
}

if (empty($links)) {
    return;
}

?>
<tr>
  <th><?= $this->translate('Actions') ?></th>
  <td><?= implode("\n ", $links) . "\n" ?></td>
</tr>