Google Map JS SDK - Convert window coordinates to LatLng

script.js

let x = 100; //relative left position of the point 
let y = 200; //relative top position of the point
let projection = map.getProjection();
let scale = Math.pow(2, map.getZoom());
let topRight = projection.fromLatLngToPoint(map.getBounds().getNorthEast());
let bottomLeft = projection.fromLatLngToPoint(map.getBounds().getSouthWest());
const reversePoint = new google.maps.Point(
    bottomLeft.x + (x / scale),
    topRight.y + (y / scale)
);
return projection.fromPointToLatLng(reversePoint); // converted value of x, y to LatLng