The following URLs seem to refer to an old library (Babylon.js v4.2.0-alpha.16 or 27)
https://playground.babylonjs.com/indexWebGPU.html
https://www.babylonjs.com/demos/webgpu/forestwebgpu
https://www.babylonjs.com/demos/webgpu/oneSphereWebGPU
https://www.babylonjs.com/demos/webgpu/oneHelmetWebGPU
https://www.babylonjs.com/demos/webgpu/tenThousandSpheresWebGPU
Some of these samples are referenced from the WebGPU Wiki.