Get public IP address (wan IP address) using XMLHttpRequest JavaScript function

publicip.js

function getPublicIP() {
  var xhr = new XMLHttpRequest();
  xhr.open("GET", "http://httpbin.org/ip", true); // false for synchronous request
  xhr.onload = function(e) {
    if (xhr.readyState === 4) {
      if (xhr.status === 200) {
        let yourWanIP = JSON.parse(xhr.responseText).origin;
          // do what you want to do with the IP address
          // ... eg. log it to the console
          console.log(yourWanIP);  
      } else {
        console.error(xhr.statusText);
      }
    }
  }
  xhr.onerror = function(e) {
    console.error(xhr.statusText);
  };
  xhr.send(null);
}

getPublicIP();