icingaweb2/application/views/scripts/config/authentication/remove.phtml

<div class="controls">
    <?= $this->tabs->showOnlyCloseButton() ?>
</div>
<div class="content">
    <h1 tabindex="0" id="authentication-remove">
        <?= $this->translate('Remove Backend'); ?>
    </h1>
    <div>
        <?= $form; ?>
    </div>
</div>