API Call & backend/controller

// API CALL

createByID: (toCreate, id) =>
      axios.post(`${resourceURL}/${id}`, toCreate, {
        headers: { Authorization: getBearerTokenFromCookie() },
      })



// CONTROLLER POST METHOD

@ApiOperation(value = "Posts a users application")
    @PostMapping("/{applicantId}")
    public ResponseEntity<UserAssignmentApplication> postUserApplication(
            @RequestBody UserAssignmentApplication userAssignmentApplication,
            @PathVariable Long applicantId) {
        try {
            userAssignmentApplicationInterface.createUserAssignmentApplication(userAssignmentApplication, applicantId);
        } catch (Exception e) {
            e.printStackTrace();
            return ResponseEntity.notFound().build();
        }
        return ResponseEntity.ok().build();
    }



// SERVICE METHOD

@Override
    public void createUserAssignmentApplication(UserAssignmentApplication userAssignmentApplication, Long applicantId) throws Exception {
        UserAssignment userAssignment;
        User applicant;
        Long userAssignmentId = userAssignmentApplication.getUserAssignment().getId();

        boolean applicationAlreadyExists = repository.existsUserAssignmentApplicationByApplicantIdAndUserAssignmentId(applicantId, userAssignmentId);
        if (applicationAlreadyExists) {
            throw new UserAssignmentApplicationAlreadyExistsException();
        }

        try {
            userAssignment = userAssignmentService.findById(userAssignmentId);
        } catch (Exception e) {
            e.printStackTrace();
            return;
        }

        try {
            applicant = userService.findById(applicantId);
        } catch (Exception e) {
            e.printStackTrace();
            return;
        }

        userAssignmentApplication.setApplicant(applicant);
        userAssignmentApplication.setUserAssignment(userAssignment);
        userAssignmentApplication.setStatus(AssignmentApplicationStatus.PENDING);
        repository.save(userAssignmentApplication);
    }