i can't upload image using google cloud bucket;; what's wrong?

[semin98]

<title>Document</title>

<!--<script src="/static/js/ckeditor5.js"></script>-->
<script src="https://cdn.ckeditor.com/ckeditor5/35.0.1/classic/ckeditor.js"></script>

editor
<textarea name="content" id="content">{{#data}}{{data.content}}{{/data}}</textarea>
<script>

ClassicEditor.create( document.querySelector( '#content' ), {
    language: "ko",
    ckfinder : {

        uploadUrl : "/image/upload",
    }
} )
.catch(error => {
    console.error(error);
});

</script>

package com.grepp.ck.controller;

//import com.grepp.ck.service.GCSFileUploadService;
//import org.springframework.beans.factory.annotation.Autowired;
//import org.springframework.http.ResponseEntity;
//import org.springframework.stereotype.Controller;
//import org.springframework.beans.factory.annotation.Value;
//import org.springframework.web.bind.annotation.PostMapping;
//import org.springframework.web.bind.annotation.RequestParam;
//import org.springframework.web.bind.annotation.ResponseBody;
//import org.springframework.web.bind.annotation.RestController;
//import org.springframework.web.multipart.MultipartFile;
//import org.springframework.web.multipart.MultipartRequest;
//
//import java.io.IOException;
//import java.util.Map;
//
//@RestController
//public class ImageUploadController {
//
// @Autowired
// private GCSFileUploadService gcsFileUploadService;
//
// @value("${gcp.bucket.name}")
// private String bucketName;
//
// @PostMapping("/image/upload")
// public ResponseEntity<?> uploadImage(@RequestParam("upload") MultipartFile file) throws IOException {
// try {
// String imageUrl = gcsFileUploadService.uploadFile(file);
//
// return ResponseEntity.ok("{"url":"" + imageUrl + ""}");
// } catch (IOException e) {
// return ResponseEntity.status(500).body("{"error":"" + e.getMessage() + ""}");
// }
// }

import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.Storage;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

@RestController
public class ImageUploadController {

@Autowired
private Storage storage;

@Value("${gcp.bucket.name}")
private String bucketName;

@PostMapping("/image/upload")
public ResponseEntity<?> uploadImage(@RequestParam("upload") MultipartFile file) {
    try {
        // GCS 버킷 객체를 가져옵니다.
        Bucket bucket = storage.get(bucketName);
        String fileName = file.getOriginalFilename();

        // GCS에 파일을 직접 업로드합니다.
        Blob blob = bucket.create(fileName, file.getBytes(), file.getContentType());

        // 업로드된 파일의 URL을 반환합니다.
        String imageUrl = blob.getMediaLink();

        // CKEditor의 응답 형식에 맞게 JSON 응답을 반환합니다.
        return ResponseEntity.ok("{\"url\":\"" + imageUrl + "\"}");

    } catch (Exception e) {
        // 오류가 발생하면 500 상태 코드와 함께 에러 메시지를 반환합니다.
        return ResponseEntity.status(500).body("{\"error\":\"" + e.getMessage() + "\"}");
    }
}

}

help me plz