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

<?php

// We are not interested in notifications for OK or pending objects
if (in_array((int) $object->state, array(0, 99))) {
    return;
}

?>
<tr>
  <th><?= $this->translate('Notifications') ?></th>
  <td>
<?php

if ($object->current_notification_number > 0) {
    if ((int) $object->current_notification_number === 1) {
        $msg = sprintf(
            $this->translate('A notication has been sent for this issue %s ago'),
            $this->timeSince($object->last_notification)
        );
    } else {
        $msg = sprintf(
            $this->translate('%s notications have been sent for this issue'),
            $object->current_notification_number
        ) . '<br />' . sprintf(
            $this->translate('The last one occured %s ago'),
            $this->timeSince($object->last_notification)
        );
    }
    echo $msg;
} else {
    echo $this->translate('No notification has been sent for this issue');
}
?>
  </td>
</tr>