notifications-admin/app/broadcast_areas/source_files/Demo.geojson

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "id": "sizewell",
        "name": "Sizewell",
        "count_of_phones": 700
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [[
          [1.58242, 52.22035],
          [1.58491, 52.19521],
          [1.59971, 52.19325],
          [1.62352, 52.19372],
          [1.62599, 52.21901],
          [1.58242, 52.22035]
        ]]
      }
    }
  ]
}