Geoguessr custom avatar

function encodeImageFileAsURL(callback) {
  var input = document.createElement('input');
  input.type = 'file';
  input.onchange = (e) => {
    var reader = new FileReader();
    reader.onloadend = function() {
      callback(reader.result);
    }
    reader.readAsDataURL(e.target.files[0]);
  }
  input.click();
}

function sendRequest(data){
  var xmlhttp = new XMLHttpRequest();   // new HttpRequest instance
  var theUrl = 'https://www.geoguessr.com/api/v4/avatar';
  xmlhttp.open("POST", theUrl);
  xmlhttp.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
  xmlhttp.send(JSON.stringify({
    "skin": 6,
    "equippedIds": [],
    "mugshotPin": data,
    "fullBodyPin": data,
  }));
}

encodeImageFileAsURL(d => sendRequest(d));