안녕하세요. 다시 질문이 있어서 글을 올립니다. 오류나는 부분만 글을 올립니다.
오류 내용은 An error happened during template parsing (template: "class path resource [templates/daywork_detail.html]")
Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Error during execution of processor 'org.thymeleaf.spring6.processor.SpringTextareaFieldTagProcessor' (template: "daywork_detail" - line 33, col 19)
Neither BindingResult nor plain target object for bean name 'dayworkanswerForm' available as request attribute
at org.springframework.web.servlet.support.BindStatus.(BindStatus.java:153) ~[spring-webmvc-6.0.11.jar:6.0.11]

        <!-- 답변 반복 끝  -->
    <!-- 답변 작성 -->
   <form th:action="@{|/dayworkanswer/create/${daywork.id}|}" th:object="${dayworkanswerForm}" method="post" class="my-3">
        <div class="alert alert-danger" role="alert" th:if="${#fields.hasAnyErrors()}">
            <div th:each="err : ${#fields.allErrors()}" th:text="${err}" />
        </div>
        <textarea th:field="*{content}" rows="10" class="form-control"></textarea>
        <input type="submit" value="답변등록" class="btn btn-primary my-2">
    </form>
</div>
</html>

import jakarta.validation.constraints.NotEmpty;

import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
public class DayWorkAnswerForm {
      @NotEmpty(message = "내용은 필수항목입니다.")
      private String content;
}

@RequestMapping("/dayworkanswer")
@RequiredArgsConstructor
@Controller
public class DayWorkAnswerController {

    private final DayWorkService dayworkService;
    private final DayWorkAnswerService dayworkanswerService;

    @PostMapping("/create/{id}")
    public String createAnswer(Model model, @PathVariable("id") Integer id, @Valid DayWorkAnswerForm dayworkanswerForm, BindingResult bindingResult) {
        DayWork daywork = this.dayworkService.getDayWork(id);
        // TODO: 답변을 저장한다. 
        if (bindingResult.hasErrors()) {
            model.addAttribute("daywork", daywork);
            return "daywork_detail";
        }
        this.dayworkanswerService.create(daywork, dayworkanswerForm.getContent());

        return String.format("redirect:/daywork/detail/%s", id);
    }

}