Hello i’ve been developing a MERN app, instead of MongoDB is MySQL, so its MySQl ERN app.
My site is a simple blog, post blogs with a name, and the content of the blog.
So i implemented CORS while developing all in localhost (server and frontend sides). Everything works fine
So i deploy my app, the server side of the page is located on Render host service, and the Frontend side is located on Netlify
When i do a POST request through axios to post a blog, CORS error and the following: “Response to preflight request doesn’t pass access control check: It does not have HTTP ok status.” That didn’t happen when I made all the requests with localhost (server and frontend side).

I have some theories but i dont know how to solve none of those: send a 200 status, implement some headers into CORS
My code to do the POST request is the following:
index.js

import express from 'express'
import cors from 'cors'
import {PORT} from './config.js'
import indexRoutes from './routes/index.routes.js'
import blogRoutes from './routes/blogs.routes.js'

const app = express()

app.use(express.json())
app.use(cors({origin: true}))

app.use(indexRoutes)
app.use(blogRoutes)

app.listen(PORT)
console.log(`server running on port ${PORT}`)

blogapi.js

export const createBlogRequest = async (blog) =>{
    await axios.post('https://fullstack-mern-blog.onrender.com/blogs', blog)
}

Poster.jsx

import React, { useEffect, useState } from "react";
import { createBlogRequest } from "../api/blosg.api";
import { useParams } from "react-router-dom";

function Poster() {
  const [newUser, setNewUser] = useState("");
  const [newPost, setNewPost] = useState("");

  const params = useParams()
  
  const handleSubmit = async (e) => {
    e.preventDefault();
    console.log(targeted)
    try {
      const response = await createBlogRequest(targeted)
      console.log(response)
    } catch (error) {
      console.error(error)
    }
    setNewUser('')
    setNewPost('')
  }
  const targeted = {name: newUser, post: newPost}

  return (
    <>
    <h1>{params.id ? "edita el post" : "Postea algo "}</h1>
      <form onSubmit={handleSubmit}>
        <input
          type="text"
          name="user"
          placeholder="escribi tu nombre..."
          onChange={(e) => setNewUser(e.target.value)}
          value={newUser}
        />
        <br />
        <textarea
          name="post"
          cols="30"
          rows="10"
          placeholder="escribi algo dale..."
          onChange={(e) => setNewPost(e.target.value)}
          value={newPost}
        ></textarea>
        <br />
        <button type="submit">Subir</button>
      </form>
    </>
  );
}

export default Poster;

Any answer will be received