whmcsDNSManager/modules/addons/DNSManager2/templates/admin/formFields/containers/modal.tpl

<div class="form-horizontal">
    {foreach from=$hidden item=field}
        {$field->html}
    {/foreach}
    {foreach from=$fields item=field}
            {if $field->opentag}
                <div class="form-group">
            {/if}
              {$field->html}
            {if $field->closetag}
                </div>
            {/if}
    {/foreach}
</div>