- A data source for vector tiles; there's a lot of options: https://stadiamaps.com (my company), https://maptiler.com/ & https://jawg.io (other core contributing companies), among others.
- A style that matches. I'm not aware of an open source style that closely mirrors OSM's style using MapLibre GL Styles (also forked from Mapbox). OSM Bright is pretty close: https://github.com/mapbox/osm-bright / https://github.com/openmaptiles/osm-bright-gl-style.