Alter headers

const handler: ExportedHandler = {
  async fetch(request: Request) {
    const response = await fetch(request);

    // Clone the response so that it's no longer immutable
    const newResponse = new Response(response.body, response);

    // Add a custom header with a value
    newResponse.headers.append(
      "x-workers-hello",
      "Hello from Cloudflare Workers"
    );

    // Delete headers
    newResponse.headers.delete("x-header-to-delete");
    newResponse.headers.delete("x-header2-to-delete");

    // Adjust the value for an existing header
    newResponse.headers.set("x-header-to-change", "NewValue");
    return newResponse;
  },
};
export default handler;