If I'm not mistaking, you want to open the URL in the application it self (without navigating to external -Safari- browser). Well, if that's the case, you should use UIWebView:
You can use the UIWebView class to embed web content in your app. To
do so, create a UIWebView object, attach it to a window, and send it a
request to load web content. You can also use this class to move back
and forward in the history of webpages, and you can even set some web
content properties programmatically.
WebViewController:
I suggest to add a UIWebView into a ViewController (called WebViewController) and present the ViewController when needed; ViewController on storyboard should looks like:

DON'T forget to assign a Storyboard ID for it.
And the ViewController:
class WebViewController: UIViewController {
@IBOutlet weak private var webVIew: UIWebView!
var urlString: String?
override func viewDidLoad() {
if let unwrappedUrlString = urlString {
let urlRequest = URLRequest(url: URL(string: unwrappedUrlString)!)
webVIew.loadRequest(urlRequest)
}
}
@IBAction private func donePressed(_ sender: Any) {
dismiss(animated: true, completion: nil)
}
}
Usage:
Consider that you want present it when the user taps a button in another ViewController:
class ViewController: UIViewController {
@IBAction private func donePressed(_ sender: Any) {
let stoyrboard = UIStoryboard(name: "Main", bundle: nil)
// withIdentifier: the used storyboard ID:
let webViewController = stoyrboard.instantiateViewController(withIdentifier: "WebViewController") as! WebViewController
webViewController.urlString = "https://www.google.com/"
}
}
Or specifically for your case (selecting a cell):
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
// withIdentifier: the used storyboard ID:
let webViewController = stoyrboard.instantiateViewController(withIdentifier: "WebViewController") as! WebViewController
webViewController.urlString = "URL GOES HERE..."
}
Hope this helped.