I’ve tried to post data from FrontEnd with ReactJS to BackEnd Spring Boot but it has AxiosError: Request failed with status code 500

could you guy tell what wrong with my code? why i can’t post new product to backend?

here is my code:

BackEnd:
Product Controller

package com.tranxuanphong.example04.controller;

import java.util.List;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import com.tranxuanphong.example04.entity.Product;
import com.tranxuanphong.example04.service.ProductService;

import lombok.AllArgsConstructor;

@RestController
@AllArgsConstructor
@RequestMapping("api/products")
@CrossOrigin(origins = { "http://localhost:3000"}, exposedHeaders = "Content-Range")

public class ProductController {

    private ProductService productService;

    // Create Product REST API
    @PostMapping
    public ResponseEntity<Product> createProduct(@RequestBody Product product) {
        Product savedProduct = productService.createProduct(product);
        return new ResponseEntity<>(savedProduct, HttpStatus.CREATED);
    }

    // Get All Products REST API
    // http://localhost:8080/api/Products
    @GetMapping
    public ResponseEntity<List<Product>> getAllProducts() {
        List<Product> products = productService.getAllProducts();
        return new ResponseEntity<>(products, HttpStatus.OK);
    }    
}

React: Product.js

const createProduct = (event) => {
        event.preventDefault();
      
        if (title !== "" || body!== "" || price !== "" || category !== "0" || photo !== "") {
            let product = {
                title: title,
                description: body,
                price: price,
                photo: photo,
                category_id: parseInt(category)
            }

            POST_ADD_PRODUCT(`products`, product).then(item => {
                // console.log('item:',item);
                if(item.data===1){
                    setCheckAdd(true);
                }
            })
        }
        else {
            alert("Not enough information");
        }
    }

React: apiService.js

export function callApi(endpoint, method = 'GET', body) {
    return axios({
        method: method,
        url : `${API_URL}/${endpoint}`,
        data : body,   
    })      
    .catch(e => {   
        console.log(e)
    })
}

export function POST_ADD_PRODUCT (endpoint, data) {
    return callApi(endpoint, "POST", data);
}

i’ve been trying to post this from my FrontEnd ReactJS to BackEnd all day but i can’t
however I tried Postman and it worked fine with post and get
so i think my FrontEnd have some problem maybe