Models only load in sandcastle

I am new to Cesium. I am able to load models just fine in sandcastle but when I try to do it from a file on my computer or on another domain the models will not show up. I am using this url “
I also downloaded the CesiumBalloon.glb file from gethub and stored it locally but it still will not load. I get no error message

@Maporama welcome to the Cesium community!

You should see an error message if you check your browser console. Are you using a local web server? You’d need to do that in order to serve models locally.

What kind of application are you building? It might be easiest if you upload your models to Cesium ion ( and that’ll take care of hosting it for you.