[keycloak-user] Services behind a Proxy that offloads SSL

Hi there, I have a service running in a JBoss server, that I want to secure via the keycloak adapter. The server is behind a proxy, that offloads SSL, so the server itself gets traffic as http. When the server redirects to keycloak for authentication, the redirect URL supplied to keycloak is http, not https. How can I ensure, that a redirect URL is an https URL? Greetings, Malte