How to change coordinate type in GeoJSON(leaflet)?

Question

Geolocation

There is a huge GeoJSON file, but it has a different coordinate format (attached in a screenshot)
The question is, is it possible somehow to display this on a map without converting to latLng. And one more question, what kind of coordinate format is this? Everything he found in Arcgis is called basemap.

Answer 1

TopoJSON

Answer 2

You just have rectangular coordinates (in projection), not geographic (in degrees). Accordingly, you either enter a description of this projection in the leaflet so that it can recalculate the degrees itself, or you convert and already apply it with ready-made degrees.