src/main/resources/templates/fragment/footer.html

<html lagn="ko" 
      xmlns:th="http://www.thymeleaf.org">
      
    <!--footerFragment 선언-->
    <div th:fragment="footerFragment" style="height: 4em;text-align: center;">
        <div class="shadow-none p-3 mb-5 bg-light rounded">Daeucna .Ltd</div>
    </div>
    
</html>