Creating a sphere of 1km radius on the map

using System;
using UnityEngine;

public class DrawCircleAroundPlayer : MonoBehaviour
{
    /// <summary>
    /// Radius of the circle
    /// </summary>
    public float radiusKM = 0.1f;

    /// <summary>
    /// Number of segments
    /// </summary>
    public int segments = 32;

    private OnlineMapsMarker3DInstance onlineMapsMarker;
    private OnlineMaps map;

    private void Start()
    {
        map = OnlineMaps.instance;
        onlineMapsMarker = GetComponent<OnlineMapsMarker3DInstance>();
        name = onlineMapsMarker.marker.label;
        DrawCircle();
    }

    /// <summary>
    /// Draw circle around player with set radius
    /// </summary>
    private void DrawCircle()
    {
        // Get the coordinates under cursor
        double lng = onlineMapsMarker.marker.position.x;
        double lat = onlineMapsMarker.marker.position.y;

        // Get the coordinate at the desired distance
        double nlng, nlat;
        OnlineMapsUtils.GetCoordinateInDistance(lng, lat, radiusKM, 90, out nlng, out nlat);

        double tx1, ty1, tx2, ty2;

        // Convert the coordinate under cursor to tile position
        map.projection.CoordinatesToTile(lng, lat, 20, out tx1, out ty1);

        // Convert remote coordinate to tile position
        map.projection.CoordinatesToTile(nlng, nlat, 20, out tx2, out ty2);

        // Calculate radius in tiles
        double r = tx2 - tx1;

        // Create a new array for points
        OnlineMapsVector2d[] points = new OnlineMapsVector2d[segments];

        // Calculate a step
        double step = 360d / segments;

        // Calculate each point of circle
        for (int i = 0; i < segments; i++)
        {
            double px = tx1 + Math.Cos(step * i * OnlineMapsUtils.Deg2Rad) * r;
            double py = ty1 + Math.Sin(step * i * OnlineMapsUtils.Deg2Rad) * r;
            map.projection.TileToCoordinates(px, py, 20, out lng, out lat);
            points[i] = new OnlineMapsVector2d(lng, lat);
        }

        // Create a new polygon to draw a circle
        OnlineMapsDrawingElementManager.AddItem(new OnlineMapsDrawingPoly(points, Color.green, 3));
    }
}