Send data from QR scanning client to server

I’m new to fetch/post/get thing and trying to figure out a way to solve this problem.
Currently i have a client that is a QR scanner.
This qr scanner digests a link and splits it into variables. These variables are then supposed to be sent to the proxy which in turn requests from the server. This in turn will return specific information based on the variables from the server to the proxy. this information will then be sent from proxy to client and later be displayed on the same page the QR scanner is initiated from.

The proxy is run on localhost:9094 and the client is run on localhost:3000

The issue i’m having is that I can’t seem to find a way send over my variables from the client to the proxy.

My QR client:

//OnScan this method is called
handleScan = data => {
if (data) {
    //Splitting the link 
    const trailingData = data.split(/[?]/).pop();
    let arr = trailingData.split(/.w+=/).filter(Boolean);

    //Sending the array of variables to another function
    this.getOutletInfo(arr);
    
  }
}

getOutletInfo(arr)
{
fetch('http://localhost:9094/getOutletInfo',{mode:'cors'},
  {
      method: "GET",
      data: {
        outletId: arr[3],
        providerCode: arr[1]
      }
  })
  .then(function(response) {
    return response.json();
  })
  .then(function(myJson) {
    console.log(myJson);
  });
}

The proxy:::

 let app = require('express')();
 let server = require('http').Server(app);
 app.use(bodyParser.json());       // to support JSON-encoded bodies
 app.use(methodOverride()); 
 server.listen('9094', 'localhost', function () {
     console.log("App listening on port 9094");
 });

  //..code..

 //Should be app.post but is .get for now. When sending request to server with the 
 //message below, the response shall be added to the client that is run on 
 //localhost:3000.
 app.get('/getOutletInfo', function (req, res) {
    res.header('Access-Control-Allow-Origin', '*');
    let message = {
        "outletId": req.body.outletId,
        "providerCode": req.body.providerCode
    };
    console.log("DEBUG" + " " + req.outletId);
    //This method below handles the connection between proxy and server - works as 
    //intended
    handleSynchronousRequest(message, "APP_GET_OUTLET_STATUS_REQUEST", res);
});

Help and explanation would be highly appreciated!