yarn add -D @miniflare/tre@3.0.0-next.12

export default {
  async fetch(request, env) {
    if (request) {
      console.log(request.cf);
      return new Response("Hello cf");
    } else {
      return new Response("Hello world");
    }
  }
}

wrangler dev

fetch()

curl -u [YOUR_KEY_ID]:[YOUR_KEY_SECRET]

js
export default {
  fetch(req) {
    const username = "user";
    const password = "passwd";
    const b64 = btoa(`${username}:${password}`);

    return fetch("https://httpbin.org/basic-auth/user/passwd", {
      headers: {
        Authorization: `Basic ${b64}`,
      },
    });
  },
};