func webView(_ webView: WKWebView, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {

        let user = "user"
        let password = "pass"
        let credential = URLCredential(user: user, password: password, persistence: URLCredential.Persistence.forSession)
        challenge.sender?.use(credential, for: challenge)
        completionHandler(URLSession.AuthChallengeDisposition.useCredential, credential)
}