Make only points within UIBezierPath button selectable

[timswift]

My swift code features a custom shape button made from a UIBezierPath. The code should only call the func press if it the user touches the red part if the user touches the green part the func press should not be called. Right now if you touch the green part the func is still called.

import UIKit

class ViewController: UIViewController {
    let customButton = UIButton(frame: CGRect(x: 100.0, y: 100.0, width: 200.0, height: 140.0))
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        customButton.backgroundColor = UIColor.green
        
        let aPath = UIBezierPath()
        
        aPath.move(to: CGPoint(x: 50, y: 0))
        
        aPath.addLine(to: CGPoint(x: 200.0, y: 40.0))
        aPath.addLine(to: CGPoint(x: 160, y: 140))
        aPath.addLine(to: CGPoint(x: 40.0, y: 140))
        aPath.addLine(to: CGPoint(x: 0.0, y: 40.0))
        
        aPath.close()
        
        let layer = CAShapeLayer()
        layer.fillColor = UIColor.red.cgColor
        layer.strokeColor = UIColor.red.cgColor
        layer.path = aPath.cgPath
        
        customButton.layer.addSublayer(layer)
        
        self.view.addSubview(customButton)
        customButton.addTarget(self, action: #selector(press), for: .touchDown)
        
    }
    
    @objc func press(){
        print("hit")
    }
    
    
}