so this is my code, whenever I gonna insert data into my database it returns error 400 I don’t know the reason, I did other crud operations and it was fine.

import React from 'react';
import { Formik, Form, Field} from 'formik';
import axios from 'axios';

const AddProduct = () => {

    const handleFileChange = (event, setFieldValue) => {
        const file = event.currentTarget.files[0];
        const reader = new FileReader();
        reader.onloadend = () => {
            const blob = new Blob([reader.result], {
                type: file.type
            });
            setFieldValue('pic', blob);
        };
        reader.readAsArrayBuffer(file);
    };

  return (
    <Formik
        initialValues={{
            name: '',
            desc: '', // You can use a date picker library for this field
            pic: '',
            price: '',
        }}
        onSubmit={(values) => {

            const formData = new FormData();

            formData.append('name', values.name);
            formData.append('category', values.category);
            formData.append('desc', values.desc);
            formData.append('price', parseFloat(values.price).toFixed(2));
            formData.append('pic', values.pic);

            axios.post('http://localhost:3002/products/', formData)
                .then(response => {
                    console.log(response.data);
                })
        }}
        >
        {({ isSubmitting, setFieldValue }) => (
            <Form className='addproduct-form-container'>
                <Field type="text" name="name" placeholder="عنوان محصول" className='addproduct-product-name'/>
                <Field type="text" name="desc" placeholder="توضیحات" className='addproduct-product-desc'/>
                <input type="file" name="pic" placeholder="تصویر محصول" className='addproduct-product-pic' onChange={ (event) => handleFileChange(event, setFieldValue) }/>
                <Field type="number" name="price" placeholder="قیمت محصول (تومان)" className='addproduct-product-price' />
                <button type="submit" disabled={isSubmitting}  className='addproduct-product-submit'>انجام</button>
            </Form>
        )}
    </Formik>
  )
}

export default AddProduct

when I log the form data it returns values and values are right but when I submit it returns error 400
it seems that the reason is notNull violation but as I said I logged the values before sending them.

routes/products.js:

const express = require('express');
const router = express.Router();
const Products = require('../models/Product');

//Create a Product
router.post('/', async (req, res) => {
    try {
        const product = await Products.create(req.body);
        res.status(201).json(product);
    } catch (error) {
        res.status(400).json({ error: error.message });
    }
});

// Read All Products 
router.get('/', async (req, res) => {
    try {
        const products = await Products.findAll();

        const imageBlobs = products.map(image => ({
            id: image.id,
            title: image.name,
            description: image.description,
            category: image.category,
            price: image.price,
            image: image.image.toString('base64')
        }));


        res.status(200).json(imageBlobs);

    } catch (error) {
        res.status(400).json({ error: error.message });
    }
});

router.get('/:id', async (req, res) => {
    try {
        const product = await Products.findByPk(req.params.id);
        if (product) {
            res.status(200).json(product);
        } else {
            res.status(404).json({ error: 'Product not found' });
        }
    } catch (error) {
        res.status(400).json( { error: error.message });
    }
});

// Delete a Product By Id
router.delete('/:id', async (req, res) => {
    try {
        const product = await Products.findByPk(req.params.id);
        if (product) {
            await product.destroy();
            res.status(204).send();
        } else {
            res.status(404).json( {error: 'Product Not Found.'});
        } 
    } catch (error) {
        res.status(400).json({ error: error.message });
    }
});

module.exports = router;