Zoom level always 16

[R1im]

Im trying to use my own custom geojson with: var osmb = new OSMBuildings(map).load('https://localhost:3000/osm/{z}/{x}/{y}.json');

Zoom level(z) is always 16 no matter what level use has. Where can I find more documentation for OSMB+leaflet? Seems that leaflet website took it down