identity server auto-logout when user idle - not working

Question

I am using identity server 3. Currently, timeout is working based on setup, But I need the solution for when user idle timeout should happen.

 AuthenticationOptions = new AuthenticationOptions
                {
                    EnableLocalLogin = config.EnableLocalLogin,
                    EnableSignOutPrompt = false,
                    EnablePostSignOutAutoRedirect = true,
                    PostSignOutAutoRedirectDelay = 0,
                    RememberLastUsername = false,
                    IdentityProviders = (x, signInAs) => ConfigureIdentityProviders(x, signInAs, config, awsConfig),
                    CookieOptions = new CookieOptions
                    {
                        AllowRememberMe = false,
                        //ExpireTimeSpan = TimeSpan.FromMinutes(2),
                        //SlidingExpiration = false,
                        //IsPersistent=false
                    }
                },

I need the solution for when user's idle timeout should happen.