iOS Swift how to create button that looks like Clickable Text Link

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        self.navigationItem.title = "Main View"
        
        //Button looks like Clickable Text Link
        addButton1()
        
        
   }
    
    func addButton1(){
        
        let button1 = UIButton()
        button1.translatesAutoresizingMaskIntoConstraints = false
        self.view.addSubview(button1)
        
        button1.translatesAutoresizingMaskIntoConstraints = false
        
        let attributedString = NSMutableAttributedString.init(string: "This is a BUTTON")
        attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: 1, range:
            NSRange.init(location: 0, length: attributedString.length))
        attributedString.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.blue, range:
            NSRange.init(location: 0, length: attributedString.length))
        attributedString.addAttribute(NSAttributedString.Key.font, value: UIFont.systemFont(ofSize: 24.0), range: NSRange.init(location: 0, length: attributedString.length))
        button1.setAttributedTitle(attributedString, for: .normal)
        
        var allConstraints: [NSLayoutConstraint] = []
        let views = ["view": view!, "button1": button1]
        
        let horizontalConstraints = NSLayoutConstraint.constraints(
            withVisualFormat: "H:|-[button1]-(>=10)-|", metrics: nil, views: views)
        allConstraints += horizontalConstraints
        
        let verticalConstraints = NSLayoutConstraint.constraints(
            withVisualFormat: "V:|-(>=40)-[button1]", metrics: nil, views: views)
        allConstraints += verticalConstraints
        
        NSLayoutConstraint.activate(allConstraints)
 
        button1.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
        
    }
    
    @objc func buttonAction(sender: UIButton!) {
        if let buttonTitle = sender.titleLabel?.text {
            print(buttonTitle + ": button tapped!")
        }
    }

}