How do you cover a MapBox map with a semi-transparent overlay?

Question

I would like to put an opacity: 0.7 layer over the whole map, but in between the geography tiles and some dots I'm going to draw at specific lat/lngs. How can I add a semi-transparent overlay to a MapBox map in between my dots and the land/water?

Answer 1

Here is the sample code from the mapbox-gl lib https://docs.mapbox.com/mapbox-gl-js/example/adjust-layer-opacity/

Its basically a part of the style specification, where you need to create a layer on map styles