I've solved this problem following https://community.jalios.com/jcms/jx_73408/en/windows-authentication-waffle-plugin-12?cid=jc_84212.
You have to configure the web browser in order for Windows authentication to be sent to remote HTTP server.
To configure Internet Explorer for automatic logon
Open the Internet Options dialog box by choosing Internet Options either from Control Panel or from the Tools menu in Internet Explorer.
In the Internet Options dialog box, on the Security tab, select Local intranet, and then click Custom Level.
In the Security Settings dialog box, under Logon, select Automatic logon only in Intranet zone, and then click OK.
In the Internet Options dialog box on the Security Settings tab with Local intranet still selected, click Sites.
In the Local intranet dialog box, click Advanced.
In the next dialog box (also titled Local intranet), type the URL of your JCMS web site (for example, https://intranet.mycompany.com) in the Add this Web site to the zone box, and then click Add.
In the Local intranet dialog, box click OK.
In the original Local intranet dialog box, click OK.
In the Internet Options dialog box, click OK.
Google Chrome
Google chrome is automatically configured to send the proper credential.
Firefox
The domain of the HTTP server must be added to the trusted domain for Negotiate authentication, using preference network.negotiate-auth.trusted-uris, either through about:config (in address bar) or in prefs.js (in user profil directory).
Read Mozilla.org - Integrated Authentication for more information.