CORS headers missing when using Axios in NextJS - axios

Question

I'm using a NestJS backend with a NextJS frontend, both hosted seperately.
NestJS Backend
I enabled CORS in the backend as follows:
app.enableCors({ credentials: true, origin: process.env.FRONTEND_URL });
When using cors-test.codehappy.dev to check the CORS headers everything looks good. All headers are present and the access-control-allow-origin header points to the right domain where the front-end is hosted on.
NextJS Frontend
On the NextJS frontend I'm using Axios to make request to the backend (the exact same url as used above).However, when creating a request the preflight request in Chrome is missing all CORS headers. The Axios instance below is imported when a HTTP request is needed.
import Axios from 'axios';
const api = Axios.create({
baseURL: process.env.BACKENDURL,
withCredentials: true
});
export default api;
The error in the console:
The preflight request:

Answer 1

in next.config.js
module.exports = {
//avoiding CORS error, more here: https://vercel.com/support/articles/how-to-enable-cors
async headers() {
return [
{
// matching all API routes
source: "/api/:path*",
headers: [
{ key: "Access-Control-Allow-Credentials", value: "true" },
{ key: "Access-Control-Allow-Origin", value: "*" },
{ key: "Access-Control-Allow-Methods", value: "GET,OPTIONS,PATCH,DELETE,POST,PUT" },
{ key: "Access-Control-Allow-Headers", value: "X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version" },
]
}
]
},
}