[Aerogear-users] Revoke (logout) token - Android

Hello, I'm using AeroGear to connect to a Keycloak server and retrieve data. When I tried it for the first time it opened a WebView and promted me to enter my password and username. Then when it was succesful I opened MainActivity. Now my question is how can I implement the logout functionality, since the app dosen't ask me again for my credentials (username, password) but just sends a succes and opens MainActivity. Thank you for your help in advance. Best regards, Mitja