geohash.kql

// Geohash GeoJSON collection
datatable(lng:real, lat:real)
[
    -73.975212, 40.789608,
    -73.916869, 40.818314,
    -73.989148, 40.743273,
]
| project geohash = geo_point_to_geohash(lng, lat, 5)
| project geohash_polygon = geo_geohash_to_polygon(geohash)
| summarize geohash_polygon_lst = make_list(geohash_polygon)
| project pack(
    "type", "Feature",
    "geometry", pack("type", "GeometryCollection", "geometries", geohash_polygon_lst),
    "properties", pack("name", "Geohash polygons collection"))

map.geojson