custom has been blocked by CORS policy: Request header field request-header-attrs is not allowed by Access-Control-Allow-Headers in preflight response. code example
Example 1: what is cors
“CORS” stands for Cross-Origin Resource Sharing.
It allows you to make requests from one website to another website
in the browser, which is normally prohibited by another browser policy
called the Same-Origin Policy (SOP).
Example 2: how to use cros
npm i cors
const cors = require('cors');
const express = require('express');
const app = express();
app.us(cors());
Example 3: how to use cros
app.use not app.us