Redirect `403 Forbidden` to a different page

export default {
  async fetch(request) {
    // Send original request to the origin
    const response = await fetch(request);
    // Check if origin responded with 403 status code
    if (response.status == 403) {
      // If so, redirect to this URL
      const destinationURL = "https://example.com";
      // With this status code
      const statusCode = 301;
      // Serve redirect
      return Response.redirect(destinationURL, statusCode);
    }
    // Otherwise, serve origin's response
    else {
      return response;
    }
  },
};