Errors and suggestions

getting 2 errors:
Assets/Scripts/TakeScreenshot.cs(23,39): error CS1525: Unexpected symbol private' Assets/Scripts/TakeScreenshot.cs(13,17): error CS1525: Unexpected symbol }’
Also any suggestion to improve

using UnityEngine;
using System.Collections;
 
public class TakeScreenshot : MonoBehaviour
{    


	public string captureKey = "f2";
	void Start (){
		if (PlayerPrefs.HasKey("ScreenshotNumber") == false)
		{
			PlayerPrefs.SetInt("ScreenshotNumber", 1)
		}
	}
    void Update()
    {
		private int screenshotCount = PlayerPrefs.GetInt("ScreenshotNumber")
        if (Input.GetKeyDown(captureKey))
        {        
            string screenshotFilename;
            do
			{
				private int ssn = 0
				ssn = PlayerPrefs.GetInt("ScreenshotNumber") + 1
				PlayerPrefs.SetInt("ScreenshotNumber", ssn)
				screenshotFilename = "screenshot" + screenshotCount + ".png";
 
            } while (System.IO.File.Exists(screenshotFilename));
 
            Application.CaptureScreenshot(screenshotFilename);
			
        }
    }
}

First, the ‘private’ keyword is used for instance variables…the ones you declare at the top of the file that are outside of any function. It is an error to use ‘private’ inside a function, so remove ‘private’ from lines 17 and 23.

Next you are missing many ‘;’. You need them at the end of lines: 12, 17, 23, 24, and 25…and there may be more.

do not use private inside of the method:

private int screenshotCount = PlayerPrefs.GetInt("ScreenshotNumber")

int screenshotCount = PlayerPrefs.GetInt("ScreenshotNumber");