gistfile1.txt

function getUrlVars() {
  var vars = {};
  var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m,key,value) {
      vars[key] = value;
  });
  return vars;
}

$(document).ready(function() {
  $.ajax({                     
      type: "GET",                     
      url: 'https://p8dmwkfw4d.execute-api.ap-southeast-1.amazonaws.com/default/ruby-function',
      data: 'username='.getUrlVars().username,
      contentType: 'application/json',      
      success: function(res){ 
          console.log(res);},
      error: function(){
          console.log('Something get wrong!');}
  }); 
});