public override Vector2 GetScreenPosition(double lng, double lat)
{
    double tlx, tly, brx, bry;
    map.GetTileCorners(out tlx, out tly, out brx, out bry);
    int maxX = 1 << map.zoom;
    if (tlx > brx) brx += maxX;

    double px, py;
    map.projection.CoordinatesToTile(lng, lat, map.zoom, out px, out py);

    if (px + maxX / 2 < tlx) px += maxX;

    double rx = (px - tlx) / (brx - tlx) - 0.5;
    double ry = 0.5 - (py - tly) / (bry - tly);

    Bounds bounds = spriteRenderer.sprite.bounds;
    Vector3 size = bounds.size;

    rx *= size.x;
    ry *= size.y;

    Vector3 worldPoint = transform.localToWorldMatrix.MultiplyPoint(new Vector3((float)rx, (float)ry, bounds.center.z));
    return Camera.main.WorldToScreenPoint(worldPoint);
}

using UnityEngine;

public class LogCoordinatesUnderCursor:MonoBehaviour
{
    private void OnGUI()
    {
        Vector2 coords = OnlineMapsControlBase.instance.GetCoords();

        GUIStyle style = new GUIStyle(GUI.skin.label);
        style.fontSize = 24;
        style.normal.textColor = Color.red;

        GUILayout.Label("Top Left: " + OnlineMaps.instance.topLeftPosition.ToString("F6"), style);
        GUILayout.Label("Bottom Right: " + OnlineMaps.instance.bottomRightPosition.ToString("F6"), style);
        GUILayout.Label("Coords: " + coords.ToString("F6"), style);
        GUILayout.Label("Input: " + OnlineMapsControlBase.instance.GetInputPosition(), style);
        GUILayout.Label("Screen Position: " + OnlineMapsControlBase.instance.GetScreenPosition(coords), style);
    }
}