Mapbox custom visual choropleth question

[sumant-28]

I saw your YouTube video here and have produced a visual like this where the map is outlined but there is no fill. I am wondering if there is a silly mistake that I have made or whether this custom visual is deprecated. Other custom map visuals have deprecated over time which is why I am not completely certain it is just my error. Having said that I think it is more likely to be my error but I don't see where I went wrong