gl-ref

This directive is used to create an internal reference to any element in your controller and access the DOM element.

<div gl-ref="anything"></div>

So, we create a reference called anything and we will fetch it in the following JS code:

Controller.$refs.get("anything").innerHTML = "Test";

After this, the innerHTML of the element will be set to Test. Keep in mind that the returned value of $refs.get return a plain DOM element with no added properties from GreenLight.