How to implement isUserInteractionEnabled

If you mean var isUserInteractionEnabled: Bool { get set } as the provided code, it is not something to use, but to understand what it is. It explains that isUserInteractionEnabled is a read-write property of type Bool.

To use isUserInteractionEnabled, you may need to write something like this:

import UIKit

class ViewController: UIViewController {
    
    @IBOutlet var imageView: UIImageView!
    //...

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        imageView.isUserInteractionEnabled = true
        //...
    }

    //...
}

You should better show your code when you ask something, that explains how experienced you are and helps getting better answers which will fit for your code.

And to make a good communication in the forums, you should better reply to answers or comments to your posts.

You can also enable interaction directly in Interface Builder, with the Attributes Inspector.