[keycloak-user] Kerberos auth

Hi everybody ! I am implementing kerberos authentication for my keycloak users but a problem is blocking me. When I get the page "401 unauthorized", a warning appears "JavaScript is disabled. We strongly recommend to enable it. You were unable to login via Kerberos. Click the button below to login via an alternative method" and I'm redirected automatically. Do you know what it is? Cordially