Uncaught (in promise) error

export default {
  async fetch(request, env) {
    const url = new URL(request.url);
    const key = url.pathname.slice(1);

    const { pathname } = new URL(request.url);
    if(pathname == "/") {
      return new Response("CDN is working! :D")
    }

    switch (request.method) {
      case 'PUT':
        if(request.headers["Authorization"] != "nop!") return "no, go away"
        await env.data.put(key, request.body, {
          customMetadata: Record({"uploader":request.headers["Author"]})
        });
        return "helo mate"
...