run keycloak with fly

as fly works so well with my custom apps, i try to move keycloak also to fly as there is even a postgres cluster available.
So i have created an organisation where postgres runs in and try to launch keycloak based on the official docker description: Running Keycloak in a container - Keycloak

without success for now!

I think that my main problems are in missing or wrong network, hostname and certificate settings.

Was anyone able to setup keycloak 18 through docker on a fly machine?