GUI.DrawTexture not working? (nothing shows up)

I have the following code attached to my main camera:

     using UnityEngine;
     using System.Collections;
     
     public class DrawGui : MonoBehaviour {
     
         public Texture crosshair;
     
         // Use this for initialization
         void Start () {
         
         }
         
         // Update is called once per frame
         void Update () {
         
         }
     
         void onGUI(){
             //draw crosshairs
             //GUI.DrawTexture(new Rect((Screen.width/2) - 3, (Screen.height/2) - 3, (Screen.width/2) + 3, (Screen.height/2) + 3),crosshair);
             GUI.DrawTexture (new Rect(10,10,60,60), crosshair, ScaleMode.ScaleToFit);
         }
     }

The image I'm trying to use for the GUI is just a small red square (as a .png file) and is inserted into the crosshair variable in the inspector.

The problem: It's not showing up! I can't seem to get the red square to appear on the screen at all. I've tried changing the values in the rect and everything. Anyone know what's up?