map.geojson

{
  "type": "Feature",
  "geometry": {
    "type": "GeometryCollection",
    "geometries": [
      {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -74.03001224983848,
              40.880202851376716
            ],
            [
              -74.03001224983848,
              40.8012684339439
            ],
            [
              -73.93598211433742,
              40.78791713450684
            ],
            [
              -73.93598211433742,
              40.86684616344577
            ],
            [
              -74.03001224983848,
              40.880202851376716
            ]
          ]
        ]
      },
      {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -73.93598211433742,
              40.86684616344577
            ],
            [
              -73.93598211433742,
              40.78791713450684
            ],
            [
              -73.84190634077625,
              40.77447756818207
            ],
            [
              -73.84190634077625,
              40.853401155678846
            ],
            [
              -73.93598211433742,
              40.86684616344577
            ]
          ]
        ]
      },
      {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -74.03001224983848,
              40.8012684339439
            ],
            [
              -74.03001224983848,
              40.7222262918358
            ],
            [
              -73.93598211433742,
              40.708880489804564
            ],
            [
              -73.93598211433742,
              40.78791713450684
            ],
            [
              -74.03001224983848,
              40.8012684339439
            ]
          ]
        ]
      }
    ]
  },
  "properties": {
    "name": "S2 Cell polygons collection"
  }
}

s2cell.kql

datatable(lng:real, lat:real)
[
    -73.956683, 40.807907,
    -73.916869, 40.818314,
    -73.989148, 40.743273,
]
| project s2_hash = geo_point_to_s2cell(lng, lat, 10)
| project s2_hash_polygon = geo_s2cell_to_polygon(s2_hash)
| summarize s2_hash_polygon_lst = make_list(s2_hash_polygon)
| project pack(
    "type", "Feature",
    "geometry", pack("type", "GeometryCollection", "geometries", s2_hash_polygon_lst),
    "properties", pack("name", "S2 Cell polygons collection"))