laravel react api : request doesn't arrived

i'm using laravel api backend with react frontend .. i'm trying to post data using axios but request dose not arrived .. here is my code in frontend

import React from 'react';
import axios from 'axios';

export default class PersonList extends React.Component {
 state = {
   product_name: '',

 }

 handleChange = event => {
   this.setState({ product_name: event.target.value });

 }

 handleSubmit = event => {
   event.preventDefault();

   const user = {
     product_name: this.state.product_name,



   };

   axios.post(`http://46.185.162.125/api/add_product`, { user })
     .then(res => {
       console.log(res);
       console.log(res.data);
     })
     .catch(error => {
   console.log(error.response)
});
 }

 render() {
   return (
     <div>
       <form onSubmit={this.handleSubmit}>
         <label>
           Name:
           <input type="text" name="product_name" onChange={this.handleChange} />
         </label>

         <button type="submit">Add</button>
       </form>
     </div>
   )
 }
}

and this is the code of backend controller

public function addProduct(Request $request)
{
        $new_product = new Product;
        $new_product->name = $request->product_name;
        $new_product->save();

        return 'success';
 }

but i get 500 error (product_name column can't be null ) and this error occurred because request dose not arrived

I trying this api on postman and it worked

How can i solve it ?

via Chebli Mohamed