headers
Headers allow you to set custom HTTP headers on the response to an incoming request on a given path.
To set custom HTTP headers you can use the headers key in next.config.js:
next.config.js module.exports = {
  async headers() {
    return [
      {
        source: '/about',
        headers: [
          {
            key: 'x-custom-header',
            value: 'my custom header value',
          },
          {
            key: 'x-another-custom-header',
            value: 'my other custom header value',
          },
        ],
      },
    ]
  },
}
headers is an async function that expects an array to be returned holding objects with source and headers properties:
source is the incoming request path pattern.
headers is an array of response header objects, with key and value properties.