How to create a function when the user stops typing in swift

I have a Ui text field and when the user stops typing after about 1 second I want a check mark to appear. I have the following code:

   @objc func getHintsFromTextField(textField: UITextField) {
       print("Hints for textField: \(textField)")
   }

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange,
    replacementString string: String) -> Bool {
    NSObject.cancelPreviousPerformRequests(
        withTarget: self,
        selector: #selector(ViewController.getHintsFromTextField),
        object: textField)
    self.perform(
        #selector(ViewController.getHintsFromTextField),
        with: textField,
        afterDelay: 3.0)
    return true
}

```    @IBAction func password3(_ sender: UITextField) {
        if textField(passwordSignUp, shouldChangeCharactersIn: NSMakeRange(5, 10), replacementString: "") == true {
            
            
            let imageView = UIImageView()
            let image1 = #imageLiteral(resourceName: "icons8-ok-28")
             imageView.image = image1
            self.passwordSignUp?.rightView = imageView
            self.passwordSignUp?.rightViewMode = UITextField.ViewMode.always
            self.passwordSignUp?.rightViewMode = .always
            errorLabel?.alpha = 0
            
        }
    }

(By the way the IBAction func password3 is on start typing) When I run my code as soon as I tap the text field the check mark appears. What am I doing wrong.

I would use something like:

func textFieldDidChangeSelection(_ textField: UITextField) {
    
    checkmarkImageView.isHidden = True
    
    let timer = Timer.scheduledTimer(timeInterval: 3.0, target: self, selector: #selector(fireTimer), userInfo: nil, repeats: true)
}

And:

@objc func fireTimer() {
    
    checkmarkImageView.isHidden = False
}

Instead of creating the imageView each time, set it up as a IBOutlet that's initially hidden.