Google Maps

In my dev environment i have plugged in "Google Maps " but the maps are not loading for the given code
does i have to plug in "Google Maps Connected System" also because in another environment where
"Google Maps version-1.0.5" and "Google Maps Connected System version-1.0.6 " are there it is working absolutely fine or i have to use
any api key for loading the maps in my environment?

{
googleMapsDisplayField(
label: "Google Map Markers",
labelPosition: "ABOVE",
validations: {},
height: "AUTO",
googleMapsApiKey: null,
mapMarkers: {
a!map(name: "1", lat: 13.067439, lng: 80.237617),
a!map(
name: "Kolkata",
lat: 22.572645,
lng: 88.363892
),
a!map(
name: "Delhi",
lat: 28.679079,
lng: 77.069710
),
a!map(
name: "Mumbai",
lat: 19.076090,
lng: 72.877426
)
},
zoomLevel: 5,
mapCenter: { lat: 20, lng: 75 },
fitBounds: false,
enableZoom: true,
enablePanning: false,
enableStreetView: true,
onMarkerSelected: null
)
}