web.whatsapp in webview

Hello, I'm trying to make the web.whatsapp website open in webview but to no avail.

It displays the following message:

Mycodeis:

publicWebViewnav;publicButtonentrar;publicvoidsetDesktopMode(WebViewwebView,booleanenabled){StringnewUserAgent=webView.getSettings().getUserAgentString();if(enabled){try{Stringua=webView.getSettings().getUserAgentString();StringandroidOSString=webView.getSettings().getUserAgentString().substring(ua.indexOf("("), ua.indexOf(")") + 1);
            newUserAgent = webView.getSettings().getUserAgentString().replace(androidOSString, "(X11; Linux x86_64)");
        } catch (Exception e) {
            e.printStackTrace();
        }
    } else {
        newUserAgent = null;
    }

    webView.getSettings().setUserAgentString(newUserAgent);
    webView.getSettings().setUseWideViewPort(enabled);
    webView.getSettings().setLoadWithOverviewMode(enabled);
    webView.reload();



}





@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);



    nav = (WebView)findViewById(R.id.vNav);
    entrar = (Button)findViewById(R.id.bEntrar);

    nav.setWebViewClient(new WebViewClient());
    nav.getSettings().setJavaScriptEnabled(true);



    entrar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {


            nav.loadUrl("https://web.whatsapp.com/");
            setDesktopMode(nav, true);


            String userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36 Edge/13";

            nav.getSettings().setUserAgentString(userAgent);




            nav.getSettings().setJavaScriptEnabled(true);
            nav.getSettings().setLoadWithOverviewMode(true);
            nav.getSettings().setUseWideViewPort(true);

            nav.getSettings().setSupportZoom(true);
            nav.getSettings().setBuiltInZoomControls(true);
            nav.getSettings().setDisplayZoomControls(false);

            nav.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
            nav.setScrollbarFadingEnabled(false);

        }
    });


}

}