I wanna use this DeckGL layer in my project. https://codepen.io/pen/?&editors=001

But I want to use custom data source. Current data source looks like this: https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/sf-bike-parking.json

const layer = new HexagonLayer({
  id: 'HexagonLayer',
  data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/sf-bike-parking.json',

I really don't know how to create COORDINATES so there would be exact GPS values matching with hexagons size. Does anyone know how to create that custom JSON file?

Thanks.