Please check inside browser’s console “navigator.gpu”. Ensure that it returns object (not undefined) on your app page(!)
I had the same problem that webGPU engine is not created by babylon. Strange problem with webGPU is supported check - #18 by TooCalm
And if it returns undefined ensure that you use https protocol or localhost URL
FYI you can create engine with method BABYLON.EngineFactory.CreateAsync(canvas, {antialias : true});
It will create webGPU if possible webGL otherwise