var links = '<a href="javascript:void();" onclick="submitForm(\'Y\'); return false;" id="ORDER_CONFIRM_BUTTON" class="fix-btn grey-btn order__btn checkout">Оформить заказ</a>';
$(".btn_box").html(links);
<a href="javascript:void();" onclick="submitForm('Y'); return false;" id="ORDER_CONFIRM_BUTTON" class="fix-btn grey-btn order__btn checkout">�������� �����</a>