For usage documentation please visit https://doc.babylonjs.com/overviews/gui
To install using npm :
npm install --save @babylonjs/core @babylonjs/gui
Afterwards it can be imported to your project using:
import { AdvancedDynamicTexture } from '@babylonjs/gui/2D';
And used as usual:
// Some awesome code
// Creates the post process
let postProcess = new AdvancedDynamicTexture("adt", 128, 128, scene);
// Some more awesome code
For more information you can have a look at our ES6 dedicated documentation.