var xhr = new XMLHttpRequest();
xhr.setRequestHeader("Authorization", "Token YOUR_SERVER_TOKEN");
xhr.open('GET', 'https://api.uber.com/v1/products?latitude=37.7759792&longitude=-122.41823');

var xhr = new XMLHttpRequest();
xhr.open('GET', 'https://api.uber.com/v1/estimates/price?start_latitude=' + position.coords.latitude + '&start_longitude=' + position.coords.longitude + '&end_latitude=53.4522973&end_longitude=-2.275001');
xhr.setRequestHeader("Authorization", "Token bTVn8k_wF3JpmHlZ0GhdbMWaLgbLMSaYof8rs-S_");
xhr.send();