Microsoft Edge has support for WebVR as you can see here https://caniuse.com/#search=webvr
The support across the main browsers looks like this at the time of writing but what is not captured here is that in order to use WebVR on a HoloLens device you need to switch on WebVR support in the about:flags.
Since RS4 was made available to HoloLens devices (see https://docs.microsoft.com/en-us/windows/mixed-reality/hololens-rs4-preview) we can run WebVR apps on there. Here’s quake in WebVR and running on a HoloLens
If you are interested in the WebVR spec then take a look here for all of the details. To get a glTF model we can use Paint3D to access the Remix online model catalogue, import a model and then export as glb.
I just want to get up and running as quickly as possible so I’m going to use a-frame where I can very easily place a glTF model into my WebVR scene declaratively using HTML like this: