https://tomchadwin.github.io/zoomstackAPI-mapbox-gl-js/
This example is intended to use only the Mapbox GL JS library, with all instances of mapbox: URIs removed. This should ensure that no Mapbox access token is required.
The other aim is to have a local copy of the style JSON, to allow people to edit as they wish.
Sign up for the Zoomstack trial at https://www.ordnancesurvey.co.uk/business-and-government/products/os-open-zoomstack.html
Find out about Mapbox GL JS at https://www.mapbox.com/mapbox-gl-js/api/