I feel like pulling my hair out; this is either super simple and i'm having brain freeze or it is not that simple.

What I want

I am trying to unshorten a shortened URL using firebase, when a user goes to:
myapp.firebaseappurl.com/url/SHORTENEDLINK
SO wont let me add a shortened URL

I would like the output to be:

{
  "url": "https://stackoverflow.com/questions/45420989/sphinx-search-how-to-use-an-empty-before-match-and-after-match"
}

What I have tried

firebase.json file:

{
  "hosting": {
    "public": "public",
    "rewrites": [ {
    "source": "/url/:item",
      "destination": "/url/:item"
    } ]
  }
}

index.js file:

const functions = require('firebase-functions');

exports.url = functions.https.onRequest((requested, response) => {

    var uri = requested.url;
    request({
        uri: uri,
        followRedirect: true
      },
      function(err, httpResponse) {
        if (err) {
          return console.error(err);
        }
        response.send(httpResponse.headers.location || uri);
      }
    );

});

Result

When I go to myapp.firebaseappurl.com/url/SHORTENEDLINK I get the following:

Error: could not handle the request