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

<?php

/** @var \Icinga\Module\Monitoring\Object\MonitoredObject $object */

if (in_array((int) $object->state, array(0, 99))) {
    // Ignore this markup if the object is in a non-problem state or pending
    return;
}

if ($object->acknowledged): ?>
    <tr>
        <th><?= $this->translate('Acknowledged') ?></th>
        <td>
            <?php if (isset($removeAckForm)) { // Form is unset if the current user lacks the respective permission
                echo $removeAckForm;
            } else {
                echo '&#45;';
            } ?>
        </td>
    </tr>
<?php else: ?>
    <tr>
        <th><?= $this->translate('Not acknowledged') ?></th>
        <td>
            <?php if ($this->hasPermission('monitoring/command/acknowledge-problem')) {
                if ($object->getType() === $object::TYPE_HOST) {
                    $ackLink = $this->href(
                        'monitoring/host/acknowledge-problem',
                        array('host' => $object->getName())
                    );
                } else {
                    $ackLink = $this->href(
                        'monitoring/service/acknowledge-problem',
                        array('host' => $object->getHost()->getName(), 'service' => $object->getName())
                    );
                }
            ?>
            <?= $this->qlink(
                $this->icon('ok') . ' ' . $this->translate('Acknowledge'),
                $ackLink,
                null,
                array('title' => $this->translate(
                    'Acknowledge this problem, suppress all future notifications for it and tag it as being handled'
                )),
                false
            ); ?>
            <?php } else {
                echo '&#45;';
            } // endif ?>
        </td>
    </tr>
<?php endif ?>