How to Custom Header for Authorization access image

Hello I have issue for use Custom Header Fetch image, how to custom header for get image ..?

```js
getPageURI: function (index, reduce, rotate) {
// reduce and rotate are ignored in this simple implementation, but we
// could e.g. look at reduce and load images from a different directory
// or pass the information to an image server
var leafStr = "000";
var imgStr = (index + 1).toString();
var re = new RegExp("0{" + imgStr.length + "}$");
var url =
"http://archive.org/download/BookReader/img/page" +
leafStr.replace(re, imgStr) +
".jpg";
console.log("ini log url " + url);
return url;
},
```