There is a version of ups that does not require keycloak (https://github.com/aerogear/aerogear-unifiedpush-server/releases/tag/1.3.1.no-auth.Final). We use that in our APB.

We should mention this fact in the installation instructions (https://aerogear.org/docs/unifiedpush/ups_userguide/index/#server-installation) because they still assume that Keycloak is a requirement.