Is it possible to have sign out button when Verint working under Windows based authentication?

Windows Authentication mode does not require either log in or log out, but instead relies on the current User.Identity provided from HttpContext. In order to switch to browsing as a different account, the user would need to switch Windows accounts.

> In order to switch to browsing as a different account, the user would need to switch Windows accounts. 

Well, it not correct

In our current configuration, where we are using Negotiate Kerberos authentication, every browser (Edge,Chrome,etc) are showing pop-up dialog where you need enter your domain credentials (only once, then they are remembered forever)

And fellas from Microsoft forums saying that returning 401 status code from sever will force user to re-enter credentials again, which may work as switch user feature

> In order to switch to browsing as a different account, the user would need to switch Windows accounts. 

Well, it not correct

In our current configuration, where we are using Negotiate Kerberos authentication, every browser (Edge,Chrome,etc) are showing pop-up dialog where you need enter your domain credentials (only once, then they are remembered forever)

And fellas from Microsoft forums saying that returning 401 status code from sever will force user to re-enter credentials again, which may work as switch user feature

You could customize the Site Banner widget and implement a custom callback file that used core_v2_page.SetStatusCode to return a 401.

Good point, thanks, we will try and return soon with result :)

Yap, this approach triggers authentication dialog if widget return 401 three times in a row, but yet all this flow was too complex, so we decided to move to the ADFS+OIDC based authentication and now there no problems with sign out

Your approach would be recommended.  Windows authentication is going to occur before the application so trying to log out is a real chicken before the egg scenario, IIS does the log in, the application just checks if it happened.