Unity error CS0029: Cannot implicitly convert type `int' to `bool' - help?

Unity error CS0029: Cannot implicitly convert type int' to bool’
I keep getting this error while trying to add a animation trigger to my C# script:

   using UnityEngine;
        using System.Collections;
        
        public class Score : MonoBehaviour {
        
        	static  int score = 0;
        	static  int highScore = 0;
        
        	Animator animator;
        
        	static public void AddPoint() {
        				score++;
        
        				if (score > highScore) { 
        						highScore = score;
        
        				}
        		}
        
        	void Start() {
        		score = 0;
        		highScore = PlayerPrefs.GetInt ("highscore", 0); {
        
        		if (highScore = 20) 
        			animator.SetTrigger ("Char2");
        		}
        	}
        
        	void OnDestroy() {
        				PlayerPrefs.SetInt ("highscore", highScore);
        		}
        	void Update () {
        				guiText.text = "Score: " + score + "

Highscore: " + highScore;
}
}

What i have here is a score system and i’m trying to make it so when the highScore is 20, it triggers an animation. But this line:

  if (highScore = 20) 
                animator.SetTrigger ("Char2");

Keeps giving me the Unity error CS0029: Cannot implicitly convert type int' to bool’
I’ve looked around for a solution but it’s confusing me further (I’m pretty new to Unity and C# so bare with me)

So my question is, how do i go about making this thing work so that when the highScore reaches 20, the animation is triggered?

You are missing one equals sign. Line should be:

if (highScore == 20)