How to build an interactive map in Appian where users can add pins by clicking and view all active parking locations?

Get value is not working, please suggest ....

a!localVariables(
  local!lat: null,
  local!lon: null,
  local!address: null,
  local!reverseGeoResult,

  a!formLayout(
    titleBar: "OSM Click → Get Coordinates + Reverse Geocode",
    contents: {

     
      /* ---------- MAP FIELD ---------- */
      /*osmMapsField(*/
        /*label: "OpenStreetMap",*/
        /*labelPosition: "ABOVE",*/
        /*height: "AUTO",*/
/**/
        /* Center map at India (sample) */
        /*mapCenter: a!map(*/
          /*latitude: 28.6139,*/
          /*longitude: 77.2090*/
        /*),*/
        /*zoomLevel: 5,*/
        /*enableMapInteraction: true,*/
        /*showLatLangInPopup: true,*/
/**/
        /* MAIN PART â`” GET CLICK COORDINATES */
        /*onClick: {*/
          /*a!save(local!lat, {{ fv!item.lat }}),*/
          /*a!save(local!lon, {{ fv!item.lon }}),*/
          /*a!save(local!address, null)*/
        /*},*/
/**/
        /* Other optional parameters (keep null unless needed) */
        /*data: null,*/
        /*hideExceptZoomButton: null,*/
        /*enablePolygonDraw: null,*/
        /*enableWatermark: null,*/
        /*enableMarkerColorChange: null,*/
        /*markerSelectedColor: null,*/
        /*clusterConfiguration: null,*/
        /*mapHeight: null,*/
        /*graphHopperKey: null,*/
        /*currentPosition: null,*/
        /*attribution: null,*/
        /*tile: null,*/
        /*maxMarkerCount: null,*/
        /*mode: "mapOnly",*/
        /*poi: null,*/
        /*customActions: null,*/
        /*onRouteChange: null,*/
        /*onLocationShare: null,*/
        /*onPOIFound: null,*/
        /*onRegionSelected: null,*/
        /*onCustomActionSelected: null,*/
        /*showFilterOn: null,*/
        /*OnMarkerClick: null*/
      /*),*/
      osmMapsField(
        label: "Pin Location",
        mapCenter: {
          latitude: 28.6139,
          longitude: 77.2090
        },
        zoomLevel: 10,
        OnMarkerClick: {
          a!save(local!lat, fv!value.lat),
          a!save(local!lon, fv!value.lon)
        },
        onClick: {
          a!save(local!lat, fv!value.lat),
          a!save(local!lon, fv!value.lon)
        }
      ),

      /* ---------- SECTION: LAT/LON ---------- */
      a!sectionLayout(
        label: "Coordinates",
        contents: {
          a!textField(
            label: "Latitude",
            readOnly: true,
            value: local!lat
          ),
          a!textField(
            label: "Longitude",
            readOnly: true,
            value: local!lon
          )
        }
      ),

      /* ---------- BUTTON: REVERSE GEOCODE ---------- */
      a!buttonLayout(
        primaryButtons: {
          a!buttonWidget(
            label: "Get Address",
            style: "SOLID",
            disabled: or(
              isnull(local!lat),
              isnull(local!lon)
            ),
            saveInto: {
              /* CALL API INTEGRATION RULE */
              a!save(
                local!reverseGeoResult,
                rule!KRS_OSM_Reverse(
                  lat: local!lat,
                  lon: local!lon
                )
              ),

              /* Extract display_name from JSON response */
              a!save(
                local!address,
                index(
                  local!reverseGeoResult,
                  "body.display_name",
                  null
                )
              )
            }
          )
        }
      ),

      /* ---------- SECTION: ADDRESS ---------- */
      a!sectionLayout(
        label: "Location Address",
        contents: {
          a!paragraphField(
            label: "Address",
            readOnly: true,
            value: local!address
          )
        }
      )
    }
    
  )
)